IEC 60335-2-51:2023
(Main)Household and similar electrical appliances - Safety - Part 2-51: Particular requirements for stationary circulation pumps for heating and service water installations
Household and similar electrical appliances - Safety - Part 2-51: Particular requirements for stationary circulation pumps for heating and service water installations
IEC 60335-2-51:2023 deals with the safety of electric stationary circulation pumps for house-hold and similar purposes intended for use in heating systems or in service water sys-tems, their rated voltage being not more than 250 V for single-phase appliances and 480 V for other appliances including direct current (DC) supplied appliances. The hydraulic and electrical parts of the pump can be in the same enclosure, so that the water flows through the motor and serves as a coolant, or they can be separated. Appliances not intended for normal household use, but that nevertheless can be a source of danger to the public, such as appliances intended to be used by laymen in shops, in light industry and on farms, are within the scope of this standard. As far as is practicable, this standard deals with the common hazards presented by ap-pliances that are encountered by all persons in and around the home. However, in gen-eral, it does not take into account:
- persons (including children) whose physical, sensory or mental capabilities; or lack of experience and knowledge prevents them from using the appliance safely without supervision or instruction;
- children playing with the appliance.
Attention is drawn to the fact that
- for appliances intended to be used in vehicles or on-board ships or aircraft, additional requirements can be necessary;
- in many countries additional requirements are specified by the national health authori-ties, the national authorities responsible for the protection of labour and similar au-thorities.
This standard does not apply to
- pumps for circulating liquids other than water;
- pumps, other than circulation pumps (IEC 60335-2-41);
- circulation pumps intended exclusively for industrial purposes;
- circulation pumps intended to be used in locations where special conditions prevail, such as the presence of a corrosive or explosive atmosphere (dust, vapour, or gas).
This fifth edition cancels and replaces the fourth edition published in 2019. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the pre-vious edition:
a) the text has been aligned with IEC 60335-1:2020;
b) some notes have been converted to normative text (Clause 1);
c) the use of separate connectors to ease the installation and establish the supply con-nection has been introduced (7.12.1, 22.102, 24.1.5, 24.1.101, 25.3);
d) clarifications related to remote operation (22.40, 22.49, 22.51).
This part 2 is to be used in conjunction with the latest edition of IEC 60335-1 and its amendments unless that edition precludes it; in that case, the latest edition that does not preclude it is used. It was established on the basis of the sixth edition (2020) of that standard.
Appareils électrodomestiques et analogues - Sécurité - Partie 2-51: Exigences particulières pour les pompes de circulation fixes pour installations de chauffage et de distribution d'eau
L'IEC 60335-2-51:2023 traite de la sécurité des pompes de circulation fixes électriques à usage domestique et analogue, destinées à être utilisées dans des installations de chauffage ou de distribution d'eau, dont la tension assignée est inférieure ou égale à 250 V pour les appareils monophasés et à 480 V pour les autres appareils, y compris les appareils alimentés en courant continu. Les parties hydrauliques et électriques de la pompe peuvent être situées dans la même enveloppe, de sorte que l'eau s'écoule à travers le moteur et serve de liquide de refroidissement, ou elles peuvent être séparées.
Les appareils non destinés à un usage domestique normal, mais qui peuvent néanmoins constituer une source de danger pour le public, tels que les appareils destinés à être utilisés par des usagers non avertis dans des magasins, chez des artisans et dans des fermes, sont compris dans le domaine d'application de la présente norme. Dans la mesure du possible, la présente norme traite des dangers courants que présentent les appareils et auxquels sont exposés tous les individus situés à l'intérieur et autour de l'habitation. Cependant, elle ne tient en général pas compte:
- des personnes (y compris des enfants) dont les capacités physiques, sensorielles ou mentales; ou le manque d'expérience et de connaissance les empêchent d'utiliser l'appareil en toute sécurité sans surveillance ou instruction;
- des enfants qui jouent avec l'appareil.
L'attention est attirée sur le fait que:
- pour les appareils destinés à être utilisés dans des véhicules ou à bord de navires ou d'avions, des exigences supplémentaires peuvent être nécessaires;
- dans de nombreux pays, des exigences supplémentaires sont spécifiées par les organismes nationaux de la santé, par les organismes nationaux responsables de la protection des travailleurs et par des organismes similaires.
La présente norme ne s'applique pas:
- aux pompes destinées à la circulation de liquides autres que l'eau;
- aux pompes autres que les pompes de circulation (IEC 60335-2-41);
- aux pompes de circulation destinées exclusivement à des usages industriels;
- aux pompes de circulation destinées à être utilisées dans des locaux qui présentent des conditions particulières, telles que la présence d'une atmosphère corrosive ou explosive (poussière, vapeur ou gaz).
Cette cinquième édition annule et remplace la quatrième édition parue en 2019. Cette édition constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a) le texte a été aligné sur l'IEC 60335-1:2020;
b) certaines notes ont été converties en texte normatif (Article 1);
c) l'emploi de connecteurs distincts a été ajouté afin de faciliter l'installation et d'effectuer le raccordement au réseau (7.12.1, 22.102, 24.1.5, 24.1.101, 25.3);
d) l'emploi de la commande à distance a été clarifié (22.40, 22.49, 22.51).
La présente partie 2 doit être utilisée conjointement avec la dernière édition de l'IEC 60335-1 et ses amendements sauf si cette édition l'exclut. Dans ce cas, la dernière édition qui n'exclut pas la présente partie 2 est utilisée. Elle a été établie sur la base de la sixième édition (2020) de cette norme.
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IEC 60335-2-51 ®
Edition 5.0 2023-12
COMMENTED VERSION
INTERNATIONAL
STANDARD
colour
inside
Household and similar electrical appliances – Safety –
Part 2-51: Particular requirements for stationary circulation pumps for heating
and service water installations
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IEC 60335-2-51 ®
Edition 5.0 2023-12
COMMENTED VERSION
INTERNATIONAL
STANDARD
colour
inside
Household and similar electrical appliances – Safety –
Part 2-51: Particular requirements for stationary circulation pumps for heating
and service water installations
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 23.080, 91.140.10 ISBN 978-2-8322-8047-8
– 2 – IEC 60335-2-51:2023 CMV © IEC 2023
CONTENTS
FOREWORD .3
INTRODUCTION .6
1 Scope .7
2 Normative references .8
3 Terms and definitions .8
4 General requirement .8
5 General conditions for the tests .8
6 Classification .8
7 Marking and instructions .9
8 Protection against access to live parts . 10
9 Starting of motor-operated appliances . 10
10 Power input and current . 10
11 Heating . 10
12 Void Charging of metal-ion batteries . 11
13 Leakage current and electric strength at operating temperature . 11
14 Transient overvoltages . 11
15 Moisture resistance . 11
16 Leakage current and electric strength . 11
17 Overload protection of transformers and associated circuits . 11
18 Endurance . 11
19 Abnormal operation . 11
20 Stability and mechanical hazards . 12
21 Mechanical strength . 12
22 Construction . 12
23 Internal wiring . 12
24 Components . 12
25 Supply connection and external flexible cords . 13
26 Terminals for external conductors . 13
27 Provision for earthing . 13
28 Screws and connections . 13
29 Clearances, creepage distances and solid insulation . 13
30 Resistance to heat and fire . 13
31 Resistance to rusting. 14
32 Radiation, toxicity and similar hazards . 14
Annexes . 15
Annex A (informative) Routine tests . 15
Bibliography . 16
List of comments . 17
Table 101 – Temperature classification of circulation pumps.9
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
SAFETY –
Part 2-51: Particular requirements for stationary circulation pumps for
heating and service water installations
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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shall not be held responsible for identifying any or all such patent rights.
This commented version (CMV) of the official standard IEC 60335-2-51:2023 edition 5.0
allows the user to identify the changes made to the previous IEC 60335-2-51:2019
edition 4.0. Furthermore, comments from IEC TC 61 experts are provided to explain the
reasons of the most relevant changes, or to clarify any part of the content.
A vertical bar appears in the margin wherever a change has been made. Additions are in
green text, deletions are in strikethrough red text. Experts' comments are identified by a
blue-background number. Mouse over a number to display a pop-up note with the com-
ment.
This publication contains the CMV and the official standard. The full list of comments is
available at the end of the CMV.
– 4 – IEC 60335-2-51:2023 CMV © IEC 2023
IEC 60335-2-51 has been prepared by IEC technical committee 61: Safety of household and
similar electrical appliances. It is an International Standard.
This fifth edition cancels and replaces the fourth edition published in 2019. This edition consti-
tutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) the text has been aligned with IEC 60335-1:2020;
b) some notes have been converted to normative text (Clause 1);
c) the use of separate connectors to ease the installation and establish the supply connection
has been introduced (7.12.1, 22.102, 24.1.5, 24.1.101, 25.3);
d) clarifications related to remote operation (22.40, 22.49, 22.51).
The text of this International Standard is based on the following documents:
Draft Report on voting
61/7008/FDIS 61/7073/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are de-
scribed in greater detail at www.iec.ch/publications.
A list of all parts of the IEC 60335 series, under the general title: Household and similar elec-
trical appliances – Safety, can be found on the IEC website.
This part 2 is to be used in conjunction with the latest edition of IEC 60335-1 and its amend-
ments unless that edition precludes it; in that case, the latest edition that does not preclude it
is used. It was established on the basis of the sixth edition (2020) of that standard.
NOTE 1 When "Part 1" is mentioned in this standard, it refers to IEC 60335-1.
This part 2 supplements or modifies the corresponding clauses in IEC 60335-1, so as to convert
that publication into the IEC standard: Particular requirements for stationary circulation pumps
for heating and service water installations.
When a particular subclause of Part 1 is not mentioned in this part 2, that subclause applies as
far as is reasonable. When this standard states "addition", "modification" or "replacement", the
relevant text in Part 1 is to be adapted accordingly.
NOTE 2 The following numbering system is used:
– subclauses, tables and figures that are numbered starting from 101 are additional to those in Part 1;
– unless notes are in a new subclause or involve notes in Part 1, they are numbered starting from 101, including
those in a replaced clause or subclause;
– additional annexes are lettered AA, BB, etc.
NOTE 3 The following print types are used:
– requirements: in roman type;
– test specifications: in italic type;
– notes: in small roman type.
Words in bold in the text are defined in Clause 3. When a definition concerns an adjective, the adjective and the
associated noun are also in bold.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
NOTE 4 The attention of National Committees is drawn to the fact that equipment manufacturers and testing
organizations can need a transitional period following publication of a new, amended or revised IEC publication in
which to make products in accordance with the new requirements and to equip themselves for conducting new or
revised tests.
It is the recommendation of the committee that the content of this publication be adopted for implementation nationally
not earlier than 12 months or later than 36 months from the date of publication.
IMPORTANT – The "colour inside" logo on the cover page of this document indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this document using a colour printer.
– 6 – IEC 60335-2-51:2023 CMV © IEC 2023
INTRODUCTION
It has been assumed in the drafting of this International Standard that the execution of its pro-
visions is entrusted to appropriately qualified and experienced persons.
Guidance documents concerning the application of the safety requirements for appliances can
be accessed via TC 61 supporting documents on the IEC website
https://www.iec.ch/tc61/supportingdocuments
This information is given for the convenience of users of this International Standard and does
not constitute a replacement for the normative text in this standard.
This standard recognizes the internationally accepted level of protection against hazards such
as electrical, mechanical, thermal, fire and radiation of appliances when operated as in normal
use taking into account the manufacturer's instructions. It also covers abnormal situations that
can be expected in practice and takes into account the way in which electromagnetic phenom-
ena can affect the safe operation of appliances.
This standard takes into account the requirements of IEC 60364 as far as possible so that there
is compatibility with the wiring rules when the appliance is connected to the supply mains.
However, national wiring rules may can differ.
If an appliance within the scope of this standard also incorporates functions that are covered
by another part 2 of IEC 60335, the relevant part 2 is applied to each function separately, as
far as is reasonable. If applicable, the influence of one function on the other is taken into ac-
count.
When a part 2 standard does not include additional requirements to cover hazards dealt with in
Part 1, Part 1 applies.
NOTE 1 This means that the technical committees responsible for the part 2 standards have determined that it is
not necessary to specify particular requirements for the appliance in question over and above the general require-
ments.
This standard is a product family standard dealing with the safety of appliances and takes prec-
edence over horizontal and generic standards covering the same subject.
NOTE 2 Horizontal and generic standards Horizontal publications, basic safety publications and group safety pub-
lications covering a hazard are not applicable since they have been taken into consideration when developing the
general and particular requirements for the IEC 60335 series of standards. For example, in the case of temperature
requirements for surfaces on many appliances, generic standards, such as ISO 13732-1 for hot surfaces, are not
applicable in addition to Part 1 or part 2 standards. 1
An appliance that complies with the text of this standard will not necessarily be considered to
comply with the safety principles of the standard if, when examined and tested, it is found to
have other features that impair the level of safety covered by these requirements.
An appliance employing materials or having forms of construction differing from those detailed
in the requirements of this standard may be examined and tested according to the intent of the
requirements and, if found to be substantially equivalent, may be considered to comply with the
standard.
NOTE 3 Standards dealing with non-safety aspects of household appliances are:
– IEC standards published by TC 59 concerning methods of measuring performance;
– CISPR 11, CISPR 14-1 and relevant IEC 61000-3 series standards concerning electromagnetic emissions;
– CISPR 14-2 concerning electromagnetic immunity;
– IEC standards published by TC 111 concerning environmental matters. 2
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
SAFETY –
Part 2-51: Particular requirements for stationary circulation pumps for
heating and service water installations
1 Scope
This clause of Part 1 is replaced by the following.
This part of IEC 60335 deals with the safety of electric stationary circulation pumps for house-
hold and similar purposes intended for use in heating systems or in service water systems, their
rated voltage being not more than 250 V for single-phase appliances and 480 V for other ap-
pliances including direct current (DC) supplied appliances. 3
NOTE 101 The hydraulic and electrical parts of the pump can be in the same enclosure, so that the water flows
through the motor and serves as a coolant, or they can be separated.
Appliances not intended for normal household use, but that nevertheless may can be a source
of danger to the public, such as appliances intended to be used by laymen in shops, in light
industry and on farms, are within the scope of this standard.
As far as is practicable, this standard deals with the common hazards presented by appliances
that are encountered by all persons in and around the home. However, in general, it does not
take into account
– persons (including children) whose
• physical, sensory or mental capabilities; or
• lack of experience and knowledge
prevents them from using the appliance safely without supervision or instruction;
– children playing with the appliance.
NOTE 102 Attention is drawn to the fact that
– for appliances intended to be used in vehicles or on-board ships or aircraft, additional re-
quirements can be necessary;
– in many countries additional requirements are specified by the national health authorities,
the national authorities responsible for the protection of labour and similar authorities.
NOTE 103 This standard does not apply to
– pumps for circulating liquids other than water;
– pumps, other than circulation pumps (IEC 60335-2-41);
– circulation pumps intended exclusively for industrial purposes;
– circulation pumps intended to be used in locations where special conditions prevail, such
as the presence of a corrosive or explosive atmosphere (dust, vapour, or gas).
– 8 – IEC 60335-2-51:2023 CMV © IEC 2023
2 Normative references
This clause of Part 1 is applicable, except as follows.
Addition:
IEC 61984:2008, Connectors – Safety requirements and tests
3 Terms and definitions
This clause of Part 1 is applicable except as follows.
3.1 Definitions relating to physical characteristics
Replacement:
3.1.9 Modification:
Replace the first paragraph with the following: 4
normal operation
operation of the circulation pump with the water pressure and flow rate adjusted within their
specified limits, so that the highest power input is attained
4 General requirement
This clause of Part 1 is applicable.
5 General conditions for the tests
This clause of Part 1 is applicable except as follows.
5.7 Addition:
The water temperature at the inlet is maintained between 0 °C and –5 °C of the value corre-
sponding to the TF class of the pump.
For circulation pumps intended to be located within the enclosure of a boiler, the tests of
Clauses 10, 11 and 13 are carried out at an ambient temperature of 55 °C or at the temperature
specified in the instructions, whichever is higher.
5.101 Circulation pumps having a three-phase motor that does not incorporate a protective
device are installed with an appropriate device, in accordance with the instructions.
6 Classification
This clause of Part 1 is applicable except as follows.
6.1 Modification:
Replace the first paragraph with the following:
Circulation pumps shall be class I, class II or class III.
6.2 Addition:
Circulation pumps shall be at least IPX2.
6.101 Circulation pumps shall be of one of the classes shown in Table 101.
Table 101 – Temperature classification of circulation pumps
Class Maximum temperature of
the circulating water
°C
TF 60 60
TF 95 95
TF 110 110
NOTE TF means Temperature of the Fluid.
Compliance is checked by inspection.
7 Marking and instructions
This clause of Part 1 is applicable except as follows.
7.1 Addition:
Circulation pumps shall be marked with
– the TF class;
– the direction of the water flow;
– the direction of rotation (for pumps having three-phase motors);
– the rated current (for pumps having three-phase motors if a protective device has to be
installed in the fixed wiring).
7.12 Modification:
The instruction concerning persons (including children) with reduced physical, sensory or men-
tal capabilities, or lack of experience and knowledge is not applicable.
The instruction regarding supervision of children is not applicable.
7.12.1 Addition:
The installation instructions shall state the substance of include the following:
– the maximum flow rate or total head;
– the maximum ambient temperature at which the pump is to be used;
– the maximum system pressure, which shall not be less than:
• 0,6 MPa for pumps for heating systems;
• 1,0 MPa for pumps for service water systems;
– the intended orientation of the pump;
– for pumps having a three-phase motor not incorporating a protective device, the substance
of the following:
– 10 – IEC 60335-2-51:2023 CMV © IEC 2023
A protective device is to be installed in the fixed wiring and its characteristics are to be
specified (for pumps having a three-phase motor not incorporating a protective device).
– for the thermal insulation of circulation pumps in heating systems, the substance of the
following:
Only the supplied kit or a kit made available by the manufacturer shall be used. It shall
be ensured that the drain openings of the motor are not sealed after installation of the
thermal insulation. 5
For circulation pumps intended for permanent connection to fixed wiring, delivered with a sep-
arate connector to ease the installation and establish the supply connection, the instructions
shall state the substance of the following:
Only use the supplied connector when installing the circulation pump. 6
8 Protection against access to live parts
This clause of Part 1 is applicable.
9 Starting of motor-operated appliances
This clause of Part 1 is not applicable.
10 Power input and current
This clause of Part 1 is applicable.
11 Heating
This clause of Part 1 is applicable except as follows.
11.2 Addition:
Circulation pumps that are only fixed by the water pipes are positioned against one wall of the
test corner and away from the other.
11.3 Addition:
The temperatures t and t are the ambient temperatures of the environment in which the pump
1 2
is installed, for instance inside the enclosure of a boiler.
11.7 Replacement Modification:
Replace the first paragraph with the following: 7
Circulation pumps are operated until steady conditions are established.
11.8 Addition:
The temperature rise limits of pumps located within the enclosure of a boiler are reduced by the
difference between the ambient temperature at which the test is carried out and 25 °C.
The temperature rise of the external enclosure is not measured.
For circulation pumps in which water flows through the motor, the temperature rise limits for
windings are increased by 5 K. The temperature rise limits are increased further by
– 5 K, if the winding insulation is class 130 (B);
– 10 K, if the winding insulation is class 155 (F) or 180 (H).
For circulation pumps in which water flows through the motor, the increase of 5 K allowed by
a
footnote to Table 3 does not apply.
12 Void Charging of metal-ion batteries
This clause of Part 1 is applicable. 8
13 Leakage current and electric strength at operating temperature
This clause of Part 1 is applicable.
14 Transient overvoltages
This clause of Part 1 is applicable.
15 Moisture resistance
This clause of Part 1 is applicable.
16 Leakage current and electric strength
This clause of Part 1 is applicable.
17 Overload protection of transformers and associated circuits
This clause of Part 1 is applicable.
18 Endurance
This clause of Part 1 is not applicable.
19 Abnormal operation
This clause of Part 1 is applicable except as follows.
19.1 Addition:
Circulation pumps are also subjected to the test of 19.101.
19.7 Addition:
The test is carried out with the water flow stopped or reduced to 5 l/min, whichever is more
unfavourable.
– 12 – IEC 60335-2-51:2023 CMV © IEC 2023
19.101 Circulation pumps are supplied at rated voltage and operated at approximately half
the maximum system pressure for 5 min, after which the water is drained off and the operation
continued for 7 h. The system is replenished with water and the pump operated again for 5 min
at approximately half the maximum system pressure.
If the pump becomes inoperable during the test, it is disconnected from the supply and the
system filled with water.
20 Stability and mechanical hazards
This clause of Part 1 is applicable.
21 Mechanical strength
This clause of Part 1 is applicable.
22 Construction
This clause of Part 1 is applicable except as follows.
22.40 Not applicable.
22.49 Not applicable.
22.51 Not applicable. 9
22.101 Circulation pumps shall withstand the water pressure occurring in normal use.
Compliance is checked by subjecting the pump to a water pressure equal to 1,2 times the
maximum system pressure for 1 min.
The pump shall not leak.
22.102 Circulation pumps intended for permanent connection to fixed wiring may be delivered
with a separate connector to ease the installation and establish the supply connection. Such a
connector shall become a non-detachable part once engaged. 10
Such a connector shall not be interchangeable with plugs and socket-outlets listed in
IEC TR 60083 or IEC 60906-1 or with appliance couplers complying with the standard sheets
of IEC 60320-3. 11
23 Internal wiring
This clause of Part 1 is applicable.
24 Components
This clause of Part 1 is applicable except as follows.
24.1.3 Modification Addition:
Switches that are only intended to be operated during installation of the pump are subjected to
100 cycles of operation.
24.1.5
NOTE 101 Connectors which are non-detachable parts once engaged are not considered to be part of an
appliance coupler. 12
24.1.101 The relevant standard for a connector as referenced in 22.102 is IEC 61984:2008.
Classification and ratings used for the tests of IEC 61984:2008 shall correspond to the ratings
of the circulation pump and its intended use.
The following clauses of IEC 61984:2008 and the corresponding test requirements in Clause 7,
are not applicable: 5.2 a), 5.4 d), 6.2.1, 6.2.2, 6.4.1, 6.4.2, 6.4.3, 6.10, 6.14.2, 6.14.3, 6.17,
6.19 and 6.20. Subclause 6.5.1 is also applicable for connectors without breaking capacity
(COC). Subclauses 6.15 and 6.16 are applicable but are modified to the circulation pump tem-
perature ratings. The tests in 7.3.6, 7.3.7 are performed when the connector referenced in
22.102 is engaged. 13
25 Supply connection and external flexible cords
This clause of Part 1 is applicable except as follows.
25.3 Addition of the following Note after the first dashed item:
NOTE 101 The set of terminals can be located in a separate connector complying with 24.1.101. 14
25.5 Addition:
Type Z attachment is allowed.
26 Terminals for external conductors
This clause of Part 1 is applicable.
27 Provision for earthing
This clause of Part 1 is applicable.
28 Screws and connections
This clause of Part 1 is applicable.
29 Clearances, creepage distances and solid insulation
This clause of Part 1 is applicable.
30 Resistance to heat and fire
This clause of Part 1 is applicable except as follows.
30.2.2 Not applicable.
– 14 – IEC 60335-2-51:2023 CMV © IEC 2023
31 Resistance to rusting
This clause of Part 1 is applicable.
32 Radiation, toxicity and similar hazards
This clause of Part 1 is applicable.
Annexes
The annexes of Part 1 are applicable except as follows.
Annex A
(informative)
Routine tests
A.23 Electric strength test
Modification Addition:
For appliances with a high leakage current, the value of 30 mA is increased to 70 mA.
– 16 – IEC 60335-2-51:2023 CMV © IEC 2023
Bibliography
The bibliography of Part 1 is applicable except as follows.
Addition:
IEC 60335-2-41, Household and similar electrical appliances – Safety – Part 2-41: Particular
requirements for pumps
List of comments
1 This revision is for alignment with IEC 60335-1:2020.
2 This revision is for alignment with IEC 60335-1:2020.
3 This revision is for alignment with IEC 60335-1:2020.
4 This revision maintains the normal operation while charging as specified in IEC 60335-1:
2020.
5 This revision is intended to separate the information to be provided in the instructions from
the "substance of" wording to be provided in the instructions.
6 This additional instruction is related to the allowance of a separate connector in Subclause
22.102. The instruction is intended to avoid the mating of male and female parts of
connectors not tested with the pump.
7 This revision maintains the Part 1 requirements for appliance outlets and socket outlets
and for charging of battery-operated appliances.
8 This revision is for alignment with IEC 60335-1:2020.
9 Additional requirements for remote operation were added to IEC 60335-1:2020. However,
the requirements in Subclauses 22.40, 22.49 and 22.51 are not applicable for stationary
circulation pumps because they are not moved while in operation, do not have accessible
moving parts and are not considered to give rise to a hazard when operated continuously,
automatically or remotely.
10 This addition allows use of a separate connector for the supply connection. Since stationary
pumps are connected to piping and the supply cord often is adapted in length some
flexibility during installation is required.
11 This is to avoid the separate connector for installation purposes that can mate with
standardised plug systems.
12 This note clarifies that the separate connector referenced in Subclause 22.102 should not
be confused with an appliance coupler because it cannot be disconnected “at will“ (IEC ref
442-07-01).
13 Subclause 24.1.101 sets the requirements for the separate connector referenced in
Subclause 22.102 and the conditions under which it must comply with selected parts of IEC
61984:2008. Requirements in clauses made not applicable are already part of IEC 60335
elsewhere or not relevant for this type of connector.
14 This is a clarification that a supply connection utilising a separate connector as referenced
in Subclause 22.102, will be allowed under the first dashed item (see Subclause 25.3 in
IEC 60335-1:2020).
___________
IEC 60335-2-51 ®
Edition 5.0 2023-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Household and similar electrical appliances – Safety –
Part 2-51: Particular requirements for stationary circulation pumps for heating
and service water installations
Appareils électrodomestiques et analogues – Sécurité –
Partie 2-51: Exigences particulières pour les pompes de circulation fixes pour
installations de chauffage et de distribution d'eau
– 2 – IEC 60335-2-51:2023 © IEC 2023
CONTENTS
FOREWORD . 3
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 8
3 Terms and definitions . 8
4 General requirement . 8
5 General conditions for the tests . 8
6 Classification . 8
7 Marking and instructions . 9
8 Protection against access to live parts . 10
9 Starting of motor-operated appliances . 10
10 Power input and current . 10
11 Heating . 10
12 Charging of metal-ion batteries . 11
13 Leakage current and electric strength at operating temperature . 11
14 Transient overvoltages . 11
15 Moisture resistance . 11
16 Leakage current and electric strength . 11
17 Overload protection of transformers and associated circuits . 11
18 Endurance . 11
19 Abnormal operation . 11
20 Stability and mechanical hazards . 12
21 Mechanical strength . 12
22 Construction . 12
23 Internal wiring . 12
24 Components . 12
25 Supply connection and external flexible cords . 13
26 Terminals for external conductors . 13
27 Provision for earthing . 13
28 Screws and connections . 13
29 Clearances, creepage distances and solid insulation . 13
30 Resistance to heat and fire . 13
31 Resistance to rusting . 13
32 Radiation, toxicity and similar hazards . 13
Annexes . 14
Annex A (informative) Routine tests . 14
Bibliography . 15
Table 101 – Temperature classification of circulation pumps . 9
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
SAFETY –
Part 2-51: Particular requirements for stationary circulation pumps for
heating and service water installations
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their prepa-
ration is entrusted to technical committees; any IEC National Committee interested in the subject dealt with may
participate in this preparatory work. International, governmental and non-governmental organizations liaising with
the IEC also participate in this preparation. IEC collaborates closely with the International Organization for Stand-
ardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all inter-
ested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any misinter-
pretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications trans-
parently to the maximum extent possible in their national and regional publications. Any divergence between any
IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, emp
...
IEC 60335-2-51 ®
Edition 5.0 2023-12
EXTENDED VERSION
INTERNATIONAL
STANDARD
colour
inside
This extended version of IEC 60335-2-51:2023 includes the content of the references made to
IEC 60335-1:2020
Household and similar electrical appliances – Safety –
Part 2-51: Particular requirements for stationary circulation pumps for heating
and service water installations
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IEC 60335-2-51 ®
Edition 5.0 2023-12
EXTENDED VERSION
INTERNATIONAL
STANDARD
colour
inside
This extended version of IEC 60335-2-51:2023 includes the content of the references made to
IEC 60335-1:2020
Household and similar electrical appliances – Safety –
Part 2-51: Particular requirements for stationary circulation pumps for heating
and service water installations
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 23.080, 91.140.10 ISBN 978-2-8322-8048-5
IEC 60335-1:2020/ISH1:2021 – 1 –
© IEC 2021
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
IEC 60335-1
Edition 6.0 2020-09
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES – SAFETY –
Part 1: General requirements
INTERPRETATION SHEET 1
This interpretation sheet has been prepared by IEC technical committee 61: Safety of
household and similar electrical appliances.
The text of this Interpretation Sheet is based on the following documents:
Draft Report on voting
61/5999/DISH 61/6009/RVDISH
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
___________
INTRODUCTION
Edition 6 of IEC 60335-1:2020 defines and introduces requirements for a detachable
power supply part of an appliance. In the document, 24.2 prohibits the use of a power
supply in a flexible cord.
QUESTION:
Does Subclause 24.2 prohibit the use of a detachable power supply part?
ANSWER
No, a "detachable power supply part" is a defined term and is not captured by the term
"power supply" as used in Subclause 24.2.
NOTE A detachable power supply part is captured by the defined term when the output of the power supply
part is detachable from the class III construction part of the appliance at:
– the power supply part, or
– the class III construction part of the appliance.
However, the supply cord (if any) does not have to be detachable from the detachable power supply part.
ICS 13.120; 97.030
IEC 60335-1:2020-09/ISH1:2021-11(en)
– 2 – IEC 60335-2-51:2023 EXV © IEC 2023
CONTENTS
FOREWORD . 6
INTRODUCTION . 9
1 Scope . 10
2 Normative references . 10
3 Terms and definitions . 15
4 General requirement . 27
5 General conditions for the tests . 27
6 Classification . 31
7 Marking and instructions . 32
8 Protection against access to live parts . 40
9 Starting of motor-operated appliances . 42
10 Power input and current . 42
11 Heating . 44
12 Charging of metal-ion batteries . 50
13 Leakage current and electric strength at operating temperature . 51
14 Transient overvoltages . 54
15 Moisture resistance . 55
16 Leakage current and electric strength . 58
17 Overload protection of transformers and associated circuits . 60
18 Endurance . 60
19 Abnormal operation . 60
20 Stability and mechanical hazards . 70
21 Mechanical strength . 72
22 Construction . 73
23 Internal wiring . 86
24 Components . 88
25 Supply connection and external flexible cords . 93
26 Terminals for external conductors . 101
27 Provision for earthing . 103
28 Screws and connections . 105
29 Clearances, creepage distances and solid insulation . 107
30 Resistance to heat and fire . 116
31 Resistance to rusting . 120
32 Radiation, toxicity and similar hazards . 120
Annex A (informative) Routine tests . 134
Annex B (normative) Battery-operated appliances, separable batteries and detachable
batteries for battery-operated appliances . 136
Annex C (normative) Ageing test on motors . 157
Annex D (normative) Thermal motor protectors . 158
Annex E (normative) Needle-flame test . 159
Annex F (normative) Capacitors . 160
Annex G (normative) Safety isolating transformers . 162
Annex H (normative) Switches . 163
Annex I (normative) Motors having basic insulation that is inadequate for the rated
voltage of the appliance . 165
Annex J (normative) Coated printed circuit boards . 167
Annex K (informative) Overvoltage categories . 168
Annex L (informative) Guidance for the measurement of clearances and creepage
distances . 169
Annex M (informative) Pollution degree . 172
Annex N (normative) Proof tracking test . 173
Annex O (informative) Selection and sequence of the tests of Clause 30 . 174
Annex P (informative) Guidance for the application of this standard to appliances
used in tropical climates . 179
Annex Q (informative) Sequence of tests for the evaluation of electronic circuits . 181
Annex R (normative) Software evaluation . 184
Annex S (informative) Guidance for the application of this standard on measurement
of power input and current based on the requirements of 10.1 and 10.2 concerning the
representative period . 198
Annex T (normative) UV-C radiation effect on non-metallic materials . 199
Annex U (normative) Appliances intended for remote communication through public
networks . 202
Bibliography . 206
Index of defined terms . 209
Figure 1 – Circuit diagram for leakage current measurement at operating temperature
for single-phase connection of class II appliances and for parts of class ll construction . 121
Figure 2 – Circuit diagram for leakage current measurement at operating temperature
for single-phase connection of other than class II appliances or parts of class ll
construction . 122
Figure 3 – Circuit diagram for leakage current measurement at operating temperature
for three-phase with neutral class II appliances and for parts of class ll construction . 123
Figure 4 – Circuit diagram for leakage current measurement at operating temperature
for three-phase with neutral appliances other than those of class II or parts of class ll
construction . 124
Figure 5 – Small part . 125
Figure 6 – Example of an electronic circuit with low-power points . 125
Figure 7 – Test finger nail . 126
Figure 8 – Flexing test apparatus . 127
Figure 9 – Constructions of cord anchorages . 128
Figure 10 – An example of parts of an earthing terminal . 129
Figure 11 – Examples of clearances . 130
Figure 12 – Example of the placement of the cylinder . 131
Figure 13 – Small parts cylinder . 132
Figure 14 – Example of a specified operating region of a lithium-ion cell during
charging . 133
Figure B.1 – Examples of battery-operated appliance constructions and application of
normative Annex B (1 of 2) . 154
Figure B.2 – Examples of correct polarity connection marking representing three
batteries . 156
– 4 – IEC 60335-2-51:2023 EXV © IEC 2023
Figure I.1 – Simulation of faults . 166
Figure L.1 – Sequence for the determination of clearances . 169
Figure L.2 – Sequence for the determination of creepage distances . 170
Figure L.3 – Measurement of clearances . 171
Figure O.1 – Tests for resistance to heat . 174
Figure O.2 – Selection and sequence of tests for resistance to fire in hand-held
appliances . 175
Figure O.3 – Selection and sequence of tests for resistance to fire in attended
appliances . 175
Figure O.4 – Selection and sequence of tests for resistance to fire in unattended
appliances . 176
Figure O.5 – Some applications of the term "within a distance of 3 mm" . 178
Figure Q.1 – Flowchart outlining the sequence of tests for the evaluation of electronic
circuits (1 of 2) . 182
Figure S.1 – Flowchart giving guidance on measurement of power input and current
concerning the representative period . 198
Table 101 – Temperature classification of circulation pumps . 32
Table 1 – Power input deviation . 42
Table 2 – Current deviation . 43
Table 3 – Maximum normal temperature rises . 47
Table 4 – Voltage for electric strength test . 54
Table 5 – Characteristics of high-voltage sources . 54
Table 6 – Impulse test voltage . 55
Table 7 – Test voltages. 59
Table 8 – Maximum winding temperature . 63
Table 9 – Maximum abnormal temperature rise . 68
Table 10 – Dimensions of cables and conduits . 94
Table 11 – Minimum cross-sectional area of conductors . 96
Table 12 – Pull force and torque . 98
Table 13 – Nominal cross-sectional area of conductors . 102
Table 14 – Torque for testing screws and nuts . 106
Table 15 – Rated impulse voltage . 108
Table 16 – Minimum clearances . 109
Table 17 – Minimum creepage distances for basic insulation . 113
Table 18 – Minimum creepage distances for functional insulation . 114
Table 19 – Minimum thickness for accessible parts of reinforced insulation consisting
of a single layer . 116
Table A.1 – Test voltages . 135
Table B.1 – Artificial source characteristics . 138
Table B.2 – Total area of openings for metal-ion cells . 146
Table B.3 – Volume of air injected at 2 070 kPa . 146
Table C.1 – Test conditions . 157
Table R.1 – General fault/error conditions . 186
Table R.2 – Specific fault/error conditions . 188
Table R.3 – Semi-formal methods . 194
Table R.4 – Software architecture specification . 194
Table R.5 – Module design specification . 195
Table R.6 – Design and coding standards . 196
Table R.7 – Software safety validation . 196
Table T.1 – Minimum property retention limits after UV-C exposure . 200
Table T.2 – Minimum electric strength for internal wiring after UV-C exposure . 201
Table U.1 – Examples of acceptable measures against unauthorised access and
transmission fault/error modes . 204
– 6 – IEC 60335-2-51:2023 EXV © IEC 2023
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
SAFETY –
Part 2-51: Particular requirements for stationary circulation pumps for
heating and service water installations
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) IEC draws attention to the possibility that the implementation of this document may involve the use of (a) patent(s).
IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in respect
thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which may
be required to implement this document. However, implementers are cautioned that this may not represent the
latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC shall
not be held responsible for identifying any or all such patent rights.
This extended version (EXV) of the official IEC Standard provides the user with the
comprehensive content of the Standard.
made to IEC 60335-1:2020.
The specific content of IEC 60335-2-51:2023 is displayed on a blue background.
IEC 60335-2-51 has been prepared by IEC technical committee 61: Safety of household and
similar electrical appliances. It is an International Standard.
This fifth edition cancels and replaces the fourth edition published in 2019. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) the text has been aligned with IEC 60335-1:2020;
b) some notes have been converted to normative text (Clause 1);
c) the use of separate connectors to ease the installation and establish the supply connection
has been introduced (7.12.1, 22.102, 24.1.5, 24.1.101, 25.3);
d) clarifications related to remote operation (22.40, 22.49, 22.51).
The text of this International Standard is based on the following documents:
Draft Report on voting
61/7008/FDIS 61/7073/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all parts of the IEC 60335 series, under the general title: Household and similar
electrical appliances – Safety, can be found on the IEC website.
This part 2 is to be used in conjunction with the latest edition of IEC 60335-1 and its
amendments unless that edition precludes it; in that case, the latest edition that does not
preclude it is used. It was established on the basis of the sixth edition (2020) of that standard.
NOTE 1 When "Part 1" is mentioned in this standard, it refers to IEC 60335-1.
This part 2 supplements or modifies the corresponding clauses in IEC 60335-1, so as to convert
that publication into the IEC standard: Particular requirements for stationary circulation pumps
for heating and service water installations.
When a particular subclause of Part 1 is not mentioned in this part 2, that subclause applies as
far as is reasonable. When this standard states "addition", "modification" or "replacement", the
relevant text in Part 1 is to be adapted accordingly.
NOTE 2 The following numbering system is used:
– subclauses, tables and figures that are numbered starting from 101 are additional to those in Part 1;
– unless notes are in a new subclause or involve notes in Part 1, they are numbered starting from 101, including
those in a replaced clause or subclause;
– additional annexes are lettered AA, BB, etc.
NOTE 3 The following print types are used:
– requirements: in roman type;
– test specifications: in italic type;
– 8 – IEC 60335-2-51:2023 EXV © IEC 2023
– notes: in small roman type.
Words in bold in the text are defined in Clause 3. When a definition concerns an adjective, the adjective and the
associated noun are also in bold.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
NOTE 4 The attention of National Committees is drawn to the fact that equipment manufacturers and testing
organizations can need a transitional period following publication of a new, amended or revised IEC publication in
which to make products in accordance with the new requirements and to equip themselves for conducting new or
revised tests.
It is the recommendation of the committee that the content of this publication be adopted for implementation nationally
not earlier than 12 months or later than 36 months from the date of publication.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this document using a colour printer.
INTRODUCTION
It has been assumed in the drafting of this International Standard that the execution of its
provisions is entrusted to appropriately qualified and experienced persons.
Guidance documents concerning the application of the safety requirements for appliances can
be accessed via TC 61 supporting documents on the IEC website
https://www.iec.ch/tc61/supportingdocuments
This information is given for the convenience of users of this International Standard and does
not constitute a replacement for the normative text in this standard.
This standard recognizes the internationally accepted level of protection against hazards such
as electrical, mechanical, thermal, fire and radiation of appliances when operated as in normal
use taking into account the manufacturer's instructions. It also covers abnormal situations that
can be expected in practice and takes into account the way in which electromagnetic
phenomena can affect the safe operation of appliances.
This standard takes into account the requirements of IEC 60364 as far as possible so that there
is compatibility with the wiring rules when the appliance is connected to the supply mains.
However, national wiring rules can differ.
If an appliance within the scope of this standard also incorporates functions that are covered
by another part 2 of IEC 60335, the relevant part 2 is applied to each function separately, as
far as is reasonable. If applicable, the influence of one function on the other is taken into
account.
When a part 2 standard does not include additional requirements to cover hazards dealt with in
Part 1, Part 1 applies.
NOTE 1 This means that the technical committees responsible for the part 2 standards have determined that it is
not necessary to specify particular requirements for the appliance in question over and above the general
requirements.
This standard is a product family standard dealing with the safety of appliances and takes
precedence over horizontal and generic standards covering the same subject.
NOTE 2 Horizontal publications, basic safety publications and group safety publications covering a hazard are not
applicable since they have been taken into consideration when developing the general and particular requirements
for the IEC 60335 series of standards.
An appliance that complies with the text of this standard will not necessarily be considered to
comply with the safety principles of the standard if, when examined and tested, it is found to
have other features that impair the level of safety covered by these requirements.
An appliance employing materials or having forms of construction differing from those detailed
in the requirements of this standard may be examined and tested according to the intent of the
requirements and, if found to be substantially equivalent, may be considered to comply with the
standard.
NOTE 3 Standards dealing with non-safety aspects of household appliances are:
– IEC standards published by TC 59 concerning methods of measuring performance;
– CISPR 11, CISPR 14-1 and relevant IEC 61000-3 series standards concerning electromagnetic emissions;
– CISPR 14-2 concerning electromagnetic immunity;
– IEC standards published by TC 111 concerning environmental matters.
– 10 – IEC 60335-2-51:2023 EXV © IEC 2023
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
SAFETY –
Part 2-51: Particular requirements for stationary circulation pumps for
heating and service water installations
1 Scope
This part of IEC 60335 deals with the safety of electric stationary circulation pumps for
household and similar purposes intended for use in heating systems or in service water systems,
their rated voltage being not more than 250 V for single-phase appliances and 480 V for other
appliances including direct current (DC) supplied appliances.
NOTE 101 The hydraulic and electrical parts of the pump can be in the same enclosure, so that the water flows
through the motor and serves as a coolant, or they can be separated.
Appliances not intended for normal household use, but that nevertheless can be a source of
danger to the public, such as appliances intended to be used by laymen in shops, in light
industry and on farms, are within the scope of this standard.
As far as is practicable, this standard deals with the common hazards presented by appliances
that are encountered by all persons in and around the home. However, in general, it does not
take into account
– persons (including children) whose
• physical, sensory or mental capabilities; or
• lack of experience and knowledge
prevents them from using the appliance safely without supervision or instruction;
– children playing with the appliance.
Attention is drawn to the fact that
– for appliances intended to be used in vehicles or on-board ships or aircraft, additional
requirements can be necessary;
– in many countries additional requirements are specified by the national health authorities,
the national authorities responsible for the protection of labour and similar authorities.
This standard does not apply to
– pumps for circulating liquids other than water;
– pumps, other than circulation pumps (IEC 60335-2-41);
– circulation pumps intended exclusively for industrial purposes;
– circulation pumps intended to be used in locations where special conditions prevail, such
as the presence of a corrosive or explosive atmosphere (dust, vapour, or gas).
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60034-1, Rotating electrical machines – Part 1: Rating and performance
IEC 60061-1, Lamp caps and holders together with gauges for the control of interchangeability
and safety – Part 1: Lamp caps
IEC 60065:2014, Audio, video and similar electronic apparatus – Safety requirements
IEC 60068-2-2, Environmental testing – Part 2-2: Tests – Test B: Dry heat
IEC 60068-2-31, Environmental testing – Part 2-31: Tests – Test Ec: Rough handling shocks,
primarily for equipment-type specimens
IEC 60068-2-75, Environmental testing – Part 2-75: Tests – Test Eh: Hammer tests
IEC 60068-2-78, Environmental testing – Part 2-78: Tests – Test Cab: Damp heat, steady state
IEC TR 60083, Plugs and socket-outlets for domestic and similar general use standardized in
member countries of IEC
IEC 60085:2007, Electrical insulation – Thermal evaluation and designation
IEC 60112:2003, Method for the determination of the proof and the comparative tracking indices
of solid insulating materials
IEC 60112:2003/AMD1:2009
IEC 60127 (all parts), Miniature fuses
IEC 60227 (all parts), Polyvinyl chloride insulated cables of rated voltages up to and including
450/750 V
IEC 60227-5:2011, Polyvinyl chloride insulated cables of rated voltages up to and including
450/750 V – Part 5: Flexible cables (cords)
IEC 60238, Edison screw lampholders
IEC 60245 (all parts), Rubber insulated cables – Rated voltages up to and including 450/750 V
IEC 60252-1:2010, AC motor capacitors – Part 1: General – Performance, testing and rating –
Safety requirements – Guidance for installation and operation
IEC 60252-1:2010/AMD1:2013
IEC 60309-2, Plugs, socket-outlets and couplers for industrial purposes – Part 2: Dimensional
interchangeability requirements for pin and contact-tube accessories
IEC 60320 (all parts), Appliance couplers for household and similar general purposes
IEC 60320-1, Appliance couplers for household and similar general purposes – Part 1: General
requirements
IEC 60320-2-3, Appliance couplers for household and similar general purposes – Part 2-3:
Appliance couplers with a degree of protection higher than IPX0
___________
There exists a consolidated edition 4.1:2009 that includes edition 4 and its Amendment 1.
There exists a consolidated edition 2.1:2013 that includes edition 2 and its Amendment 1.
– 12 – IEC 60335-2-51:2023 EXV © IEC 2023
IEC 60320-3, Appliance couplers for household and similar general purposes – Part 3: Standard
sheets and gauges
IEC 60384-14:2013, Fixed capacitors for use in electronic equipment – Part 14: Sectional
specification – Fixed capacitors for electromagnetic interference suppression and connection
to the supply mains
IEC 60384-14:2013/AMD1:2016
IEC 60417, Graphical symbols for use on equipment
IEC 60445:2017, Basic and safety principles for man-machine interface, marking and
identification – Identification of equipment terminals, conductor terminations and conductors
IEC 60529:1989, Degrees of protection provided by enclosures (IP Code)
IEC 60529:1989/AMD1:1999
IEC 60529:1989/AMD2:2013
IEC 60598-1:2014, Luminaires – Part 1: General requirements and tests
IEC 60598-1:2014/AMD1:2017
IEC 60603-11, Connectors for frequencies below 3 MHz for use with printed boards – Part 11:
Detail specification for concentric connectors (dimensions for free connectors and fixed
connectors)
IEC 60664-1:2007, Insulation coordination for equipment within low-voltage systems – Part 1:
Principles, requirements and tests
IEC 60664-3:2016, Insulation coordination for equipment within low-voltage systems – Part 3:
Use of coating, potting or moulding for protection against pollution
IEC 60664-4:2005, Insulation coordination for equipment within low-voltage systems – Part 4:
Consideration of high-frequency voltage stress
IEC 60691, Thermal-links – Requirements and application guide
IEC 60695-2-11:2014, Fire hazard testing – Part 2-11: Glowing/hot-wire based test methods –
Glow-wire flammability test method for end-products (GWEPT)
IEC 60695-2-12, Fire hazard testing – Part 2-12: Glowing/hot-wire based test methods – Glow-
wire flammability index (GWFI) test method for materials
IEC 60695-2-13, Fire hazard testing – Part 2-13: Glowing/hot-wire based test methods – Glow-
wire ignition temperature (GWIT) test method for materials
IEC 60695-10-2, Fire hazard testing – Part 10-2: Abnormal heat – Ball pressure test
IEC 60695-11-5:2016, Fire hazard testing – Part 11-5: Test flames – Needle-flame test method
– Apparatus, confirmatory test arrangement and guidance
___________
There exists a consolidated edition 4.1:2016 that includes edition 4 and its Amendment 1.
There exists a consolidated edition 2.2:2013 that includes edition 2 and its Amendment 1 and Amendment 2.
There exists a consolidated edition 8.1:2017 that includes edition 8 and its Amendment 1.
IEC 60695-11-10, Fire hazard testing – Part 11-10: Test flames – 50 W horizontal and vertical
flame test methods
IEC 60730-1:2013, Automatic electrical controls – Part 1: General requirements
IEC 60730-1:2013/AMD1:2015
IEC 60730-2-8:2018, Automatic electrical controls – Part 2-8: Particular requirements for
electrically operated water valves, including mechanical requirements
IEC 60730-2-9:2015, Automatic electrical controls – Part 2-9: Particular requirements for
temperature sensing controls
IEC 60730-2-9:2015/AMD1:2018
IEC 60730-2-10, Automatic electrical controls for household and similar use – Part 2-10:
Particular requirements for motor-starting relays
IEC 60738-1, Thermistors – Directly heated positive temperature coefficient – Part 1: Generic
specification
IEC 60799, Electrical accessories – Cord sets and interconnection cord sets
IEC 60906-1, IEC system of plugs and socket-outlets for household and similar purposes –
Part 1: Plugs and socket-outlets 16 A 250 V a.c.
IEC 60934, Circuit-breakers for equipment (CBE)
IEC 60990:2016, Methods of measurement of touch current and protective conductor current
IEC 60999-1:1999, Connecting devices – Electrical copper conductors – Safety requirements
for screw-type and screwless-type clamping units – Part 1: General requirements and particular
2 2
requirements for clamping units for conductors from 0,2 mm up to 35 mm (included)
IEC 61000-4-2, Electromagnetic compatibility (EMC) – Part 4-2: Testing and measurement
techniques – Electrostatic discharge immunity test
IEC 61000-4-3, Electromagnetic compatibility (EMC) – Part 4-3: Testing and measurement
techniques – Radiated, radio-frequency, electromagnetic field immunity test
IEC 61000-4-4, Electromagnetic compatibility (EMC) – Part 4-4: Testing and measurement
techniques – Electrical fast transient/burst immunity test
IEC 61000-4-5, Electromagnetic compatibility (EMC) – Part 4-5: Testing and measurement
techniques – Surge immunity test
IEC 61000-4-6, Electromagnetic compatibility (EMC) – Part 4-6: Testing and measurement
techniques – Immunity to conducted disturbances, induced by radio-frequency fields
IEC 61000-4-11:2020, Electromagnetic compatibility (EMC) – Part 4-11: Testing and measure-
ment techniques – Voltage dips, short interruptions and voltage variations immunity tests for
equipment with input current up to 16 A per phase
___________
There exists a consolidated edition 5.1:2015 that includes edition 5 and its Amendment 1.
There exists a consolidated edition 4.1:2018 that includes edition 4 and its Amendment 1.
– 14 – IEC 60335-2-51:2023 EXV © IEC 2023
IEC 61000-4-13:2002, Electromagnetic compatibility (EMC) – Part 4-13: Testing and
measurement techniques – Harmonics and interharmonics includi
...
IEC 60335-2-51 ®
Edition 5.0 2023-12
EXTENDED VERSION
INTERNATIONAL
STANDARD
colour
inside
This extended version of IEC 60335-2-51:2023 includes the content of the references made to
IEC 60335-1:2020
Household and similar electrical appliances – Safety –
Part 2-51: Particular requirements for stationary circulation pumps for heating
and service water installations
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IEC 60335-2-51 ®
Edition 5.0 2023-12
EXTENDED VERSION
INTERNATIONAL
STANDARD
colour
inside
This extended version of IEC 60335-2-51:2023 includes the content of the references made to
IEC 60335-1:2020
Household and similar electrical appliances – Safety –
Part 2-51: Particular requirements for stationary circulation pumps for heating
and service water installations
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 23.080, 91.140.10 ISBN 978-2-8322-8048-5
IEC 60335-1:2020/ISH1:2021 – 1 –
© IEC 2021
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
IEC 60335-1
Edition 6.0 2020-09
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES – SAFETY –
Part 1: General requirements
INTERPRETATION SHEET 1
This interpretation sheet has been prepared by IEC technical committee 61: Safety of
household and similar electrical appliances.
The text of this Interpretation Sheet is based on the following documents:
Draft Report on voting
61/5999/DISH 61/6009/RVDISH
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
___________
INTRODUCTION
Edition 6 of IEC 60335-1:2020 defines and introduces requirements for a detachable
power supply part of an appliance. In the document, 24.2 prohibits the use of a power
supply in a flexible cord.
QUESTION:
Does Subclause 24.2 prohibit the use of a detachable power supply part?
ANSWER
No, a "detachable power supply part" is a defined term and is not captured by the term
"power supply" as used in Subclause 24.2.
NOTE A detachable power supply part is captured by the defined term when the output of the power supply
part is detachable from the class III construction part of the appliance at:
– the power supply part, or
– the class III construction part of the appliance.
However, the supply cord (if any) does not have to be detachable from the detachable power supply part.
ICS 13.120; 97.030
IEC 60335-1:2020-09/ISH1:2021-11(en)
– 2 – IEC 60335-2-51:2023 EXV © IEC 2023
CONTENTS
FOREWORD . 6
INTRODUCTION . 9
1 Scope . 10
2 Normative references . 10
3 Terms and definitions . 15
4 General requirement . 27
5 General conditions for the tests . 27
6 Classification . 31
7 Marking and instructions . 32
8 Protection against access to live parts . 40
9 Starting of motor-operated appliances . 42
10 Power input and current . 42
11 Heating . 44
12 Charging of metal-ion batteries . 50
13 Leakage current and electric strength at operating temperature . 51
14 Transient overvoltages . 54
15 Moisture resistance . 55
16 Leakage current and electric strength . 58
17 Overload protection of transformers and associated circuits . 60
18 Endurance . 60
19 Abnormal operation . 60
20 Stability and mechanical hazards . 70
21 Mechanical strength . 72
22 Construction . 73
23 Internal wiring . 86
24 Components . 88
25 Supply connection and external flexible cords . 93
26 Terminals for external conductors . 101
27 Provision for earthing . 103
28 Screws and connections . 105
29 Clearances, creepage distances and solid insulation . 107
30 Resistance to heat and fire . 116
31 Resistance to rusting . 120
32 Radiation, toxicity and similar hazards . 120
Annex A (informative) Routine tests . 134
Annex B (normative) Battery-operated appliances, separable batteries and detachable
batteries for battery-operated appliances . 136
Annex C (normative) Ageing test on motors . 157
Annex D (normative) Thermal motor protectors . 158
Annex E (normative) Needle-flame test . 159
Annex F (normative) Capacitors . 160
Annex G (normative) Safety isolating transformers . 162
Annex H (normative) Switches . 163
Annex I (normative) Motors having basic insulation that is inadequate for the rated
voltage of the appliance . 165
Annex J (normative) Coated printed circuit boards . 167
Annex K (informative) Overvoltage categories . 168
Annex L (informative) Guidance for the measurement of clearances and creepage
distances . 169
Annex M (informative) Pollution degree . 172
Annex N (normative) Proof tracking test . 173
Annex O (informative) Selection and sequence of the tests of Clause 30 . 174
Annex P (informative) Guidance for the application of this standard to appliances
used in tropical climates . 179
Annex Q (informative) Sequence of tests for the evaluation of electronic circuits . 181
Annex R (normative) Software evaluation . 184
Annex S (informative) Guidance for the application of this standard on measurement
of power input and current based on the requirements of 10.1 and 10.2 concerning the
representative period . 198
Annex T (normative) UV-C radiation effect on non-metallic materials . 199
Annex U (normative) Appliances intended for remote communication through public
networks . 202
Bibliography . 206
Index of defined terms . 209
Figure 1 – Circuit diagram for leakage current measurement at operating temperature
for single-phase connection of class II appliances and for parts of class ll construction . 121
Figure 2 – Circuit diagram for leakage current measurement at operating temperature
for single-phase connection of other than class II appliances or parts of class ll
construction . 122
Figure 3 – Circuit diagram for leakage current measurement at operating temperature
for three-phase with neutral class II appliances and for parts of class ll construction . 123
Figure 4 – Circuit diagram for leakage current measurement at operating temperature
for three-phase with neutral appliances other than those of class II or parts of class ll
construction . 124
Figure 5 – Small part . 125
Figure 6 – Example of an electronic circuit with low-power points . 125
Figure 7 – Test finger nail . 126
Figure 8 – Flexing test apparatus . 127
Figure 9 – Constructions of cord anchorages . 128
Figure 10 – An example of parts of an earthing terminal . 129
Figure 11 – Examples of clearances . 130
Figure 12 – Example of the placement of the cylinder . 131
Figure 13 – Small parts cylinder . 132
Figure 14 – Example of a specified operating region of a lithium-ion cell during
charging . 133
Figure B.1 – Examples of battery-operated appliance constructions and application of
normative Annex B (1 of 2) . 154
Figure B.2 – Examples of correct polarity connection marking representing three
batteries . 156
– 4 – IEC 60335-2-51:2023 EXV © IEC 2023
Figure I.1 – Simulation of faults . 166
Figure L.1 – Sequence for the determination of clearances . 169
Figure L.2 – Sequence for the determination of creepage distances . 170
Figure L.3 – Measurement of clearances . 171
Figure O.1 – Tests for resistance to heat . 174
Figure O.2 – Selection and sequence of tests for resistance to fire in hand-held
appliances . 175
Figure O.3 – Selection and sequence of tests for resistance to fire in attended
appliances . 175
Figure O.4 – Selection and sequence of tests for resistance to fire in unattended
appliances . 176
Figure O.5 – Some applications of the term "within a distance of 3 mm" . 178
Figure Q.1 – Flowchart outlining the sequence of tests for the evaluation of electronic
circuits (1 of 2) . 182
Figure S.1 – Flowchart giving guidance on measurement of power input and current
concerning the representative period . 198
Table 101 – Temperature classification of circulation pumps . 32
Table 1 – Power input deviation . 42
Table 2 – Current deviation . 43
Table 3 – Maximum normal temperature rises . 47
Table 4 – Voltage for electric strength test . 54
Table 5 – Characteristics of high-voltage sources . 54
Table 6 – Impulse test voltage . 55
Table 7 – Test voltages. 59
Table 8 – Maximum winding temperature . 63
Table 9 – Maximum abnormal temperature rise . 68
Table 10 – Dimensions of cables and conduits . 94
Table 11 – Minimum cross-sectional area of conductors . 96
Table 12 – Pull force and torque . 98
Table 13 – Nominal cross-sectional area of conductors . 102
Table 14 – Torque for testing screws and nuts . 106
Table 15 – Rated impulse voltage . 108
Table 16 – Minimum clearances . 109
Table 17 – Minimum creepage distances for basic insulation . 113
Table 18 – Minimum creepage distances for functional insulation . 114
Table 19 – Minimum thickness for accessible parts of reinforced insulation consisting
of a single layer . 116
Table A.1 – Test voltages . 135
Table B.1 – Artificial source characteristics . 138
Table B.2 – Total area of openings for metal-ion cells . 146
Table B.3 – Volume of air injected at 2 070 kPa . 146
Table C.1 – Test conditions . 157
Table R.1 – General fault/error conditions . 186
Table R.2 – Specific fault/error conditions . 188
Table R.3 – Semi-formal methods . 194
Table R.4 – Software architecture specification . 194
Table R.5 – Module design specification . 195
Table R.6 – Design and coding standards . 196
Table R.7 – Software safety validation . 196
Table T.1 – Minimum property retention limits after UV-C exposure . 200
Table T.2 – Minimum electric strength for internal wiring after UV-C exposure . 201
Table U.1 – Examples of acceptable measures against unauthorised access and
transmission fault/error modes . 204
– 6 – IEC 60335-2-51:2023 EXV © IEC 2023
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
SAFETY –
Part 2-51: Particular requirements for stationary circulation pumps for
heating and service water installations
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) IEC draws attention to the possibility that the implementation of this document may involve the use of (a) patent(s).
IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in respect
thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which may
be required to implement this document. However, implementers are cautioned that this may not represent the
latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC shall
not be held responsible for identifying any or all such patent rights.
This extended version (EXV) of the official IEC Standard provides the user with the
comprehensive content of the Standard.
made to IEC 60335-1:2020.
The specific content of IEC 60335-2-51:2023 is displayed on a blue background.
IEC 60335-2-51 has been prepared by IEC technical committee 61: Safety of household and
similar electrical appliances. It is an International Standard.
This fifth edition cancels and replaces the fourth edition published in 2019. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) the text has been aligned with IEC 60335-1:2020;
b) some notes have been converted to normative text (Clause 1);
c) the use of separate connectors to ease the installation and establish the supply connection
has been introduced (7.12.1, 22.102, 24.1.5, 24.1.101, 25.3);
d) clarifications related to remote operation (22.40, 22.49, 22.51).
The text of this International Standard is based on the following documents:
Draft Report on voting
61/7008/FDIS 61/7073/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all parts of the IEC 60335 series, under the general title: Household and similar
electrical appliances – Safety, can be found on the IEC website.
This part 2 is to be used in conjunction with the latest edition of IEC 60335-1 and its
amendments unless that edition precludes it; in that case, the latest edition that does not
preclude it is used. It was established on the basis of the sixth edition (2020) of that standard.
NOTE 1 When "Part 1" is mentioned in this standard, it refers to IEC 60335-1.
This part 2 supplements or modifies the corresponding clauses in IEC 60335-1, so as to convert
that publication into the IEC standard: Particular requirements for stationary circulation pumps
for heating and service water installations.
When a particular subclause of Part 1 is not mentioned in this part 2, that subclause applies as
far as is reasonable. When this standard states "addition", "modification" or "replacement", the
relevant text in Part 1 is to be adapted accordingly.
NOTE 2 The following numbering system is used:
– subclauses, tables and figures that are numbered starting from 101 are additional to those in Part 1;
– unless notes are in a new subclause or involve notes in Part 1, they are numbered starting from 101, including
those in a replaced clause or subclause;
– additional annexes are lettered AA, BB, etc.
NOTE 3 The following print types are used:
– requirements: in roman type;
– test specifications: in italic type;
– 8 – IEC 60335-2-51:2023 EXV © IEC 2023
– notes: in small roman type.
Words in bold in the text are defined in Clause 3. When a definition concerns an adjective, the adjective and the
associated noun are also in bold.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
NOTE 4 The attention of National Committees is drawn to the fact that equipment manufacturers and testing
organizations can need a transitional period following publication of a new, amended or revised IEC publication in
which to make products in accordance with the new requirements and to equip themselves for conducting new or
revised tests.
It is the recommendation of the committee that the content of this publication be adopted for implementation nationally
not earlier than 12 months or later than 36 months from the date of publication.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this document using a colour printer.
INTRODUCTION
It has been assumed in the drafting of this International Standard that the execution of its
provisions is entrusted to appropriately qualified and experienced persons.
Guidance documents concerning the application of the safety requirements for appliances can
be accessed via TC 61 supporting documents on the IEC website
https://www.iec.ch/tc61/supportingdocuments
This information is given for the convenience of users of this International Standard and does
not constitute a replacement for the normative text in this standard.
This standard recognizes the internationally accepted level of protection against hazards such
as electrical, mechanical, thermal, fire and radiation of appliances when operated as in normal
use taking into account the manufacturer's instructions. It also covers abnormal situations that
can be expected in practice and takes into account the way in which electromagnetic
phenomena can affect the safe operation of appliances.
This standard takes into account the requirements of IEC 60364 as far as possible so that there
is compatibility with the wiring rules when the appliance is connected to the supply mains.
However, national wiring rules can differ.
If an appliance within the scope of this standard also incorporates functions that are covered
by another part 2 of IEC 60335, the relevant part 2 is applied to each function separately, as
far as is reasonable. If applicable, the influence of one function on the other is taken into
account.
When a part 2 standard does not include additional requirements to cover hazards dealt with in
Part 1, Part 1 applies.
NOTE 1 This means that the technical committees responsible for the part 2 standards have determined that it is
not necessary to specify particular requirements for the appliance in question over and above the general
requirements.
This standard is a product family standard dealing with the safety of appliances and takes
precedence over horizontal and generic standards covering the same subject.
NOTE 2 Horizontal publications, basic safety publications and group safety publications covering a hazard are not
applicable since they have been taken into consideration when developing the general and particular requirements
for the IEC 60335 series of standards.
An appliance that complies with the text of this standard will not necessarily be considered to
comply with the safety principles of the standard if, when examined and tested, it is found to
have other features that impair the level of safety covered by these requirements.
An appliance employing materials or having forms of construction differing from those detailed
in the requirements of this standard may be examined and tested according to the intent of the
requirements and, if found to be substantially equivalent, may be considered to comply with the
standard.
NOTE 3 Standards dealing with non-safety aspects of household appliances are:
– IEC standards published by TC 59 concerning methods of measuring performance;
– CISPR 11, CISPR 14-1 and relevant IEC 61000-3 series standards concerning electromagnetic emissions;
– CISPR 14-2 concerning electromagnetic immunity;
– IEC standards published by TC 111 concerning environmental matters.
– 10 – IEC 60335-2-51:2023 EXV © IEC 2023
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
SAFETY –
Part 2-51: Particular requirements for stationary circulation pumps for
heating and service water installations
1 Scope
This part of IEC 60335 deals with the safety of electric stationary circulation pumps for
household and similar purposes intended for use in heating systems or in service water systems,
their rated voltage being not more than 250 V for single-phase appliances and 480 V for other
appliances including direct current (DC) supplied appliances.
NOTE 101 The hydraulic and electrical parts of the pump can be in the same enclosure, so that the water flows
through the motor and serves as a coolant, or they can be separated.
Appliances not intended for normal household use, but that nevertheless can be a source of
danger to the public, such as appliances intended to be used by laymen in shops, in light
industry and on farms, are within the scope of this standard.
As far as is practicable, this standard deals with the common hazards presented by appliances
that are encountered by all persons in and around the home. However, in general, it does not
take into account
– persons (including children) whose
• physical, sensory or mental capabilities; or
• lack of experience and knowledge
prevents them from using the appliance safely without supervision or instruction;
– children playing with the appliance.
Attention is drawn to the fact that
– for appliances intended to be used in vehicles or on-board ships or aircraft, additional
requirements can be necessary;
– in many countries additional requirements are specified by the national health authorities,
the national authorities responsible for the protection of labour and similar authorities.
This standard does not apply to
– pumps for circulating liquids other than water;
– pumps, other than circulation pumps (IEC 60335-2-41);
– circulation pumps intended exclusively for industrial purposes;
– circulation pumps intended to be used in locations where special conditions prevail, such
as the presence of a corrosive or explosive atmosphere (dust, vapour, or gas).
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60034-1, Rotating electrical machines – Part 1: Rating and performance
IEC 60061-1, Lamp caps and holders together with gauges for the control of interchangeability
and safety – Part 1: Lamp caps
IEC 60065:2014, Audio, video and similar electronic apparatus – Safety requirements
IEC 60068-2-2, Environmental testing – Part 2-2: Tests – Test B: Dry heat
IEC 60068-2-31, Environmental testing – Part 2-31: Tests – Test Ec: Rough handling shocks,
primarily for equipment-type specimens
IEC 60068-2-75, Environmental testing – Part 2-75: Tests – Test Eh: Hammer tests
IEC 60068-2-78, Environmental testing – Part 2-78: Tests – Test Cab: Damp heat, steady state
IEC TR 60083, Plugs and socket-outlets for domestic and similar general use standardized in
member countries of IEC
IEC 60085:2007, Electrical insulation – Thermal evaluation and designation
IEC 60112:2003, Method for the determination of the proof and the comparative tracking indices
of solid insulating materials
IEC 60112:2003/AMD1:2009
IEC 60127 (all parts), Miniature fuses
IEC 60227 (all parts), Polyvinyl chloride insulated cables of rated voltages up to and including
450/750 V
IEC 60227-5:2011, Polyvinyl chloride insulated cables of rated voltages up to and including
450/750 V – Part 5: Flexible cables (cords)
IEC 60238, Edison screw lampholders
IEC 60245 (all parts), Rubber insulated cables – Rated voltages up to and including 450/750 V
IEC 60252-1:2010, AC motor capacitors – Part 1: General – Performance, testing and rating –
Safety requirements – Guidance for installation and operation
IEC 60252-1:2010/AMD1:2013
IEC 60309-2, Plugs, socket-outlets and couplers for industrial purposes – Part 2: Dimensional
interchangeability requirements for pin and contact-tube accessories
IEC 60320 (all parts), Appliance couplers for household and similar general purposes
IEC 60320-1, Appliance couplers for household and similar general purposes – Part 1: General
requirements
IEC 60320-2-3, Appliance couplers for household and similar general purposes – Part 2-3:
Appliance couplers with a degree of protection higher than IPX0
___________
There exists a consolidated edition 4.1:2009 that includes edition 4 and its Amendment 1.
There exists a consolidated edition 2.1:2013 that includes edition 2 and its Amendment 1.
– 12 – IEC 60335-2-51:2023 EXV © IEC 2023
IEC 60320-3, Appliance couplers for household and similar general purposes – Part 3: Standard
sheets and gauges
IEC 60384-14:2013, Fixed capacitors for use in electronic equipment – Part 14: Sectional
specification – Fixed capacitors for electromagnetic interference suppression and connection
to the supply mains
IEC 60384-14:2013/AMD1:2016
IEC 60417, Graphical symbols for use on equipment
IEC 60445:2017, Basic and safety principles for man-machine interface, marking and
identification – Identification of equipment terminals, conductor terminations and conductors
IEC 60529:1989, Degrees of protection provided by enclosures (IP Code)
IEC 60529:1989/AMD1:1999
IEC 60529:1989/AMD2:2013
IEC 60598-1:2014, Luminaires – Part 1: General requirements and tests
IEC 60598-1:2014/AMD1:2017
IEC 60603-11, Connectors for frequencies below 3 MHz for use with printed boards – Part 11:
Detail specification for concentric connectors (dimensions for free connectors and fixed
connectors)
IEC 60664-1:2007, Insulation coordination for equipment within low-voltage systems – Part 1:
Principles, requirements and tests
IEC 60664-3:2016, Insulation coordination for equipment within low-voltage systems – Part 3:
Use of coating, potting or moulding for protection against pollution
IEC 60664-4:2005, Insulation coordination for equipment within low-voltage systems – Part 4:
Consideration of high-frequency voltage stress
IEC 60691, Thermal-links – Requirements and application guide
IEC 60695-2-11:2014, Fire hazard testing – Part 2-11: Glowing/hot-wire based test methods –
Glow-wire flammability test method for end-products (GWEPT)
IEC 60695-2-12, Fire hazard testing – Part 2-12: Glowing/hot-wire based test methods – Glow-
wire flammability index (GWFI) test method for materials
IEC 60695-2-13, Fire hazard testing – Part 2-13: Glowing/hot-wire based test methods – Glow-
wire ignition temperature (GWIT) test method for materials
IEC 60695-10-2, Fire hazard testing – Part 10-2: Abnormal heat – Ball pressure test
IEC 60695-11-5:2016, Fire hazard testing – Part 11-5: Test flames – Needle-flame test method
– Apparatus, confirmatory test arrangement and guidance
___________
There exists a consolidated edition 4.1:2016 that includes edition 4 and its Amendment 1.
There exists a consolidated edition 2.2:2013 that includes edition 2 and its Amendment 1 and Amendment 2.
There exists a consolidated edition 8.1:2017 that includes edition 8 and its Amendment 1.
IEC 60695-11-10, Fire hazard testing – Part 11-10: Test flames – 50 W horizontal and vertical
flame test methods
IEC 60730-1:2013, Automatic electrical controls – Part 1: General requirements
IEC 60730-1:2013/AMD1:2015
IEC 60730-2-8:2018, Automatic electrical controls – Part 2-8: Particular requirements for
electrically operated water valves, including mechanical requirements
IEC 60730-2-9:2015, Automatic electrical controls – Part 2-9: Particular requirements for
temperature sensing controls
IEC 60730-2-9:2015/AMD1:2018
IEC 60730-2-10, Automatic electrical controls for household and similar use – Part 2-10:
Particular requirements for motor-starting relays
IEC 60738-1, Thermistors – Directly heated positive temperature coefficient – Part 1: Generic
specification
IEC 60799, Electrical accessories – Cord sets and interconnection cord sets
IEC 60906-1, IEC system of plugs and socket-outlets for household and similar purposes –
Part 1: Plugs and socket-outlets 16 A 250 V a.c.
IEC 60934, Circuit-breakers for equipment (CBE)
IEC 60990:2016, Methods of measurement of touch current and protective conductor current
IEC 60999-1:1999, Connecting devices – Electrical copper conductors – Safety requirements
for screw-type and screwless-type clamping units – Part 1: General requirements and particular
2 2
requirements for clamping units for conductors from 0,2 mm up to 35 mm (included)
IEC 61000-4-2, Electromagnetic compatibility (EMC) – Part 4-2: Testing and measurement
techniques – Electrostatic discharge immunity test
IEC 61000-4-3, Electromagnetic compatibility (EMC) – Part 4-3: Testing and measurement
techniques – Radiated, radio-frequency, electromagnetic field immunity test
IEC 61000-4-4, Electromagnetic compatibility (EMC) – Part 4-4: Testing and measurement
techniques – Electrical fast transient/burst immunity test
IEC 61000-4-5, Electromagnetic compatibility (EMC) – Part 4-5: Testing and measurement
techniques – Surge immunity test
IEC 61000-4-6, Electromagnetic compatibility (EMC) – Part 4-6: Testing and measurement
techniques – Immunity to conducted disturbances, induced by radio-frequency fields
IEC 61000-4-11:2020, Electromagnetic compatibility (EMC) – Part 4-11: Testing and measure-
ment techniques – Voltage dips, short interruptions and voltage variations immunity tests for
equipment with input current up to 16 A per phase
___________
There exists a consolidated edition 5.1:2015 that includes edition 5 and its Amendment 1.
There exists a consolidated edition 4.1:2018 that includes edition 4 and its Amendment 1.
– 14 – IEC 60335-2-51:2023 EXV © IEC 2023
IEC 61000-4-13:2002, Electromagnetic compatibility (EMC) – Part 4-13: Testing and
measurement techniques – Harmonics and interharmonics includi
...
IEC 60335-2-51 ®
Edition 5.0 2023-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Household and similar electrical appliances – Safety –
Part 2-51: Particular requirements for stationary circulation pumps for heating
and service water installations
Appareils électrodomestiques et analogues – Sécurité –
Partie 2-51: Exigences particulières pour les pompes de circulation fixes pour
installations de chauffage et de distribution d'eau
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IEC 60335-2-51 ®
Edition 5.0 2023-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Household and similar electrical appliances – Safety –
Part 2-51: Particular requirements for stationary circulation pumps for heating
and service water installations
Appareils électrodomestiques et analogues – Sécurité –
Partie 2-51: Exigences particulières pour les pompes de circulation fixes pour
installations de chauffage et de distribution d'eau
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 23.080, 91.140.10 ISBN 978-2-8322-7818-5
– 2 – IEC 60335-2-51:2023 © IEC 2023
CONTENTS
FOREWORD . 3
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 8
3 Terms and definitions . 8
4 General requirement . 8
5 General conditions for the tests . 8
6 Classification . 8
7 Marking and instructions . 9
8 Protection against access to live parts . 10
9 Starting of motor-operated appliances . 10
10 Power input and current . 10
11 Heating . 10
12 Charging of metal-ion batteries . 11
13 Leakage current and electric strength at operating temperature . 11
14 Transient overvoltages . 11
15 Moisture resistance . 11
16 Leakage current and electric strength . 11
17 Overload protection of transformers and associated circuits . 11
18 Endurance . 11
19 Abnormal operation . 11
20 Stability and mechanical hazards . 12
21 Mechanical strength . 12
22 Construction . 12
23 Internal wiring . 12
24 Components . 12
25 Supply connection and external flexible cords . 13
26 Terminals for external conductors . 13
27 Provision for earthing . 13
28 Screws and connections . 13
29 Clearances, creepage distances and solid insulation . 13
30 Resistance to heat and fire . 13
31 Resistance to rusting . 13
32 Radiation, toxicity and similar hazards . 13
Annexes . 14
Annex A (informative) Routine tests . 14
Bibliography . 15
Table 101 – Temperature classification of circulation pumps . 9
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
SAFETY –
Part 2-51: Particular requirements for stationary circulation pumps for
heating and service water installations
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their prepa-
ration is entrusted to technical committees; any IEC National Committee interested in the subject dealt with may
participate in this preparatory work. International, governmental and non-governmental organizations liaising with
the IEC also participate in this preparation. IEC collaborates closely with the International Organization for Stand-
ardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all inter-
ested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any misinter-
pretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications trans-
parently to the maximum extent possible in their national and regional publications. Any divergence between any
IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and ex-
penses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) IEC draws attention to the possibility that the implementation of this document may involve the use of (a) pa-
tent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC 60335-2-51 has been prepared by IEC technical committee 61: Safety of household and
similar electrical appliances. It is an International Standard.
This fifth edition cancels and replaces the fourth edition published in 2019. This edition consti-
tutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) the text has been aligned with IEC 60335-1:2020;
b) some notes have been converted to normative text (Clause 1);
c) the use of separate connectors to ease the installation and establish the supply connection
has been introduced (7.12.1, 22.102, 24.1.5, 24.1.101, 25.3);
– 4 – IEC 60335-2-51:2023 © IEC 2023
d) clarifications related to remote operation (22.40, 22.49, 22.51).
The text of this International Standard is based on the following documents:
Draft Report on voting
61/7008/FDIS 61/7073/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are de-
scribed in greater detail at www.iec.ch/publications.
A list of all parts of the IEC 60335 series, under the general title: Household and similar elec-
trical appliances – Safety, can be found on the IEC website.
This part 2 is to be used in conjunction with the latest edition of IEC 60335-1 and its amend-
ments unless that edition precludes it; in that case, the latest edition that does not preclude it
is used. It was established on the basis of the sixth edition (2020) of that standard.
NOTE 1 When "Part 1" is mentioned in this standard, it refers to IEC 60335-1.
This part 2 supplements or modifies the corresponding clauses in IEC 60335-1, so as to convert
that publication into the IEC standard: Particular requirements for stationary circulation pumps
for heating and service water installations.
When a particular subclause of Part 1 is not mentioned in this part 2, that subclause applies as
far as is reasonable. When this standard states "addition", "modification" or "replacement", the
relevant text in Part 1 is to be adapted accordingly.
NOTE 2 The following numbering system is used:
– subclauses, tables and figures that are numbered starting from 101 are additional to those in Part 1;
– unless notes are in a new subclause or involve notes in Part 1, they are numbered starting from 101, including
those in a replaced clause or subclause;
– additional annexes are lettered AA, BB, etc.
NOTE 3 The following print types are used:
– requirements: in roman type;
– test specifications: in italic type;
– notes: in small roman type.
Words in bold in the text are defined in Clause 3. When a definition concerns an adjective, the adjective and the
associated noun are also in bold.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
NOTE 4 The attention of National Committees is drawn to the fact that equipment manufacturers and testing
organizations can need a transitional period following publication of a new, amended or revised IEC publication in
which to make products in accordance with the new requirements and to equip themselves for conducting new or
revised tests.
It is the recommendation of the committee that the content of this publication be adopted for implementation nationally
not earlier than 12 months or later than 36 months from the date of publication.
– 6 – IEC 60335-2-51:2023 © IEC 2023
INTRODUCTION
It has been assumed in the drafting of this International Standard that the execution of its pro-
visions is entrusted to appropriately qualified and experienced persons.
Guidance documents concerning the application of the safety requirements for appliances can
be accessed via TC 61 supporting documents on the IEC website
https://www.iec.ch/tc61/supportingdocuments
This information is given for the convenience of users of this International Standard and does
not constitute a replacement for the normative text in this standard.
This standard recognizes the internationally accepted level of protection against hazards such
as electrical, mechanical, thermal, fire and radiation of appliances when operated as in normal
use taking into account the manufacturer's instructions. It also covers abnormal situations that
can be expected in practice and takes into account the way in which electromagnetic phenom-
ena can affect the safe operation of appliances.
This standard takes into account the requirements of IEC 60364 as far as possible so that there
is compatibility with the wiring rules when the appliance is connected to the supply mains.
However, national wiring rules can differ.
If an appliance within the scope of this standard also incorporates functions that are covered
by another part 2 of IEC 60335, the relevant part 2 is applied to each function separately, as
far as is reasonable. If applicable, the influence of one function on the other is taken into ac-
count.
When a part 2 standard does not include additional requirements to cover hazards dealt with in
Part 1, Part 1 applies.
NOTE 1 This means that the technical committees responsible for the part 2 standards have determined that it is
not necessary to specify particular requirements for the appliance in question over and above the general require-
ments.
This standard is a product family standard dealing with the safety of appliances and takes prec-
edence over horizontal and generic standards covering the same subject.
NOTE 2 Horizontal publications, basic safety publications and group safety publications covering a hazard are not
applicable since they have been taken into consideration when developing the general and particular requirements
for the IEC 60335 series of standards.
An appliance that complies with the text of this standard will not necessarily be considered to
comply with the safety principles of the standard if, when examined and tested, it is found to
have other features that impair the level of safety covered by these requirements.
An appliance employing materials or having forms of construction differing from those detailed
in the requirements of this standard may be examined and tested according to the intent of the
requirements and, if found to be substantially equivalent, may be considered to comply with the
standard.
NOTE 3 Standards dealing with non-safety aspects of household appliances are:
– IEC standards published by TC 59 concerning methods of measuring performance;
– CISPR 11, CISPR 14-1 and relevant IEC 61000-3 series standards concerning electromagnetic emissions;
– CISPR 14-2 concerning electromagnetic immunity;
– IEC standards published by TC 111 concerning environmental matters.
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
SAFETY –
Part 2-51: Particular requirements for stationary circulation pumps for
heating and service water installations
1 Scope
This clause of Part 1 is replaced by the following.
This part of IEC 60335 deals with the safety of electric stationary circulation pumps for house-
hold and similar purposes intended for use in heating systems or in service water systems, their
rated voltage being not more than 250 V for single-phase appliances and 480 V for other ap-
pliances including direct current (DC) supplied appliances.
NOTE 101 The hydraulic and electrical parts of the pump can be in the same enclosure, so that the water flows
through the motor and serves as a coolant, or they can be separated.
Appliances not intended for normal household use, but that nevertheless can be a source of
danger to the public, such as appliances intended to be used by laymen in shops, in light in-
dustry and on farms, are within the scope of this standard.
As far as is practicable, this standard deals with the common hazards presented by appliances
that are encountered by all persons in and around the home. However, in general, it does not
take into account
– persons (including children) whose
• physical, sensory or mental capabilities; or
• lack of experience and knowledge
prevents them from using the appliance safely without supervision or instruction;
– children playing with the appliance.
Attention is drawn to the fact that
– for appliances intended to be used in vehicles or on-board ships or aircraft, additional re-
quirements can be necessary;
– in many countries additional requirements are specified by the national health authorities,
the national authorities responsible for the protection of labour and similar authorities.
This standard does not apply to
– pumps for circulating liquids other than water;
– pumps, other than circulation pumps (IEC 60335-2-41);
– circulation pumps intended exclusively for industrial purposes;
– circulation pumps intended to be used in locations where special conditions prevail, such
as the presence of a corrosive or explosive atmosphere (dust, vapour, or gas).
– 8 – IEC 60335-2-51:2023 © IEC 2023
2 Normative references
This clause of Part 1 is applicable, except as follows.
Addition:
IEC 61984:2008, Connectors – Safety requirements and tests
3 Terms and definitions
This clause of Part 1 is applicable except as follows.
3.1 Definitions relating to physical characteristics
3.1.9 Modification:
Replace the first paragraph with the following:
operation with the water pressure and flow rate adjusted within their specified limits, so that the
highest power input is attained
4 General requirement
This clause of Part 1 is applicable.
5 General conditions for the tests
This clause of Part 1 is applicable except as follows.
5.7 Addition:
The water temperature at the inlet is maintained between 0 °C and –5 °C of the value corre-
sponding to the TF class of the pump.
For circulation pumps intended to be located within the enclosure of a boiler, the tests of
Clauses 10, 11 and 13 are carried out at an ambient temperature of 55 °C or at the temperature
specified in the instructions, whichever is higher.
5.101 Circulation pumps having a three-phase motor that does not incorporate a protective
device are installed with an appropriate device, in accordance with the instructions.
6 Classification
This clause of Part 1 is applicable except as follows.
6.1 Modification:
Replace the first paragraph with the following:
Circulation pumps shall be class I, class II or class III.
6.2 Addition:
Circulation pumps shall be at least IPX2.
6.101 Circulation pumps shall be of one of the classes shown in Table 101.
Table 101 – Temperature classification of circulation pumps
Class Maximum temperature of
the circulating water
°C
TF 60 60
TF 95 95
TF 110 110
NOTE TF means Temperature of the Fluid.
Compliance is checked by inspection.
7 Marking and instructions
This clause of Part 1 is applicable except as follows.
7.1 Addition:
Circulation pumps shall be marked with
– the TF class;
– the direction of the water flow;
– the direction of rotation (for pumps having three-phase motors);
– the rated current (for pumps having three-phase motors if a protective device has to be
installed in the fixed wiring).
7.12 Modification:
The instruction concerning persons (including children) with reduced physical, sensory or men-
tal capabilities, or lack of experience and knowledge is not applicable.
The instruction regarding supervision of children is not applicable.
7.12.1 Addition:
The installation instructions shall include the following:
– the maximum flow rate or total head;
– the maximum ambient temperature at which the pump is to be used;
– the maximum system pressure, which shall not be less than:
• 0,6 MPa for pumps for heating systems;
• 1,0 MPa for pumps for service water systems;
– the intended orientation of the pump;
– for pumps having a three-phase motor not incorporating a protective device, the substance
of the following:
A protective device is to be installed in the fixed wiring and its characteristics are to be
specified.
– for the thermal insulation of circulation pumps in heating systems, the substance of the
following:
– 10 – IEC 60335-2-51:2023 © IEC 2023
Only the supplied kit or a kit made available by the manufacturer shall be used. It shall
be ensured that the drain openings are not sealed after installation of the thermal insu-
lation.
For circulation pumps intended for permanent connection to fixed wiring, delivered with a sep-
arate connector to ease the installation and establish the supply connection, the instructions
shall state the substance of the following:
Only use the supplied connector when installing the circulation pump.
8 Protection against access to live parts
This clause of Part 1 is applicable.
9 Starting of motor-operated appliances
This clause of Part 1 is not applicable.
10 Power input and current
This clause of Part 1 is applicable.
11 Heating
This clause of Part 1 is applicable except as follows.
11.2 Addition:
Circulation pumps that are only fixed by the water pipes are positioned against one wall of the
test corner and away from the other.
11.3 Addition:
The temperatures t and t are the ambient temperatures of the environment in which the pump
1 2
is installed, for instance inside the enclosure of a boiler.
11.7 Modification:
Replace the first paragraph with the following:
Circulation pumps are operated until steady conditions are established.
11.8 Addition:
The temperature rise limits of pumps located within the enclosure of a boiler are reduced by the
difference between the ambient temperature at which the test is carried out and 25 °C.
The temperature rise of the external enclosure is not measured.
For circulation pumps in which water flows through the motor, the temperature rise limits for
windings are increased by 5 K. The temperature rise limits are increased further by
– 5 K, if the winding insulation is class 130 (B);
– 10 K, if the winding insulation is class 155 (F) or 180 (H).
For circulation pumps in which water flows through the motor, the increase of 5 K allowed by
a
footnote to Table 3 does not apply.
12 Charging of metal-ion batteries
This clause of Part 1 is applicable.
13 Leakage current and electric strength at operating temperature
This clause of Part 1 is applicable.
14 Transient overvoltages
This clause of Part 1 is applicable.
15 Moisture resistance
This clause of Part 1 is applicable.
16 Leakage current and electric strength
This clause of Part 1 is applicable.
17 Overload protection of transformers and associated circuits
This clause of Part 1 is applicable.
18 Endurance
This clause of Part 1 is not applicable.
19 Abnormal operation
This clause of Part 1 is applicable except as follows.
19.1 Addition:
Circulation pumps are also subjected to the test of 19.101.
19.7 Addition:
The test is carried out with the water flow stopped or reduced to 5 l/min, whichever is more
unfavourable.
19.101 Circulation pumps are supplied at rated voltage and operated at approximately half
the maximum system pressure for 5 min, after which the water is drained off and the operation
continued for 7 h. The system is replenished with water and the pump operated again for 5 min
at approximately half the maximum system pressure.
If the pump becomes inoperable during the test, it is disconnected from the supply and the
system filled with water.
– 12 – IEC 60335-2-51:2023 © IEC 2023
20 Stability and mechanical hazards
This clause of Part 1 is applicable.
21 Mechanical strength
This clause of Part 1 is applicable.
22 Construction
This clause of Part 1 is applicable except as follows.
22.40 Not applicable.
22.49 Not applicable.
22.51 Not applicable.
22.101 Circulation pumps shall withstand the water pressure occurring in normal use.
Compliance is checked by subjecting the pump to a water pressure equal to 1,2 times the
maximum system pressure for 1 min.
The pump shall not leak.
22.102 Circulation pumps intended for permanent connection to fixed wiring may be delivered
with a separate connector to ease the installation and establish the supply connection. Such a
connector shall become a non-detachable part once engaged.
Such a connector shall not be interchangeable with plugs and socket-outlets listed in
IEC TR 60083 or IEC 60906-1 or with appliance couplers complying with the standard sheets
of IEC 60320-3.
23 Internal wiring
This clause of Part 1 is applicable.
24 Components
This clause of Part 1 is applicable except as follows.
24.1.3 Addition:
Switches that are only intended to be operated during installation of the pump are subjected to
100 cycles of operation.
24.1.5
NOTE 101 Connectors which are non-detachable parts once engaged are not considered to be part of an
appliance coupler.
24.1.101 The relevant standard for a connector as referenced in 22.102 is IEC 61984:2008.
Classification and ratings used for the tests of IEC 61984:2008 shall correspond to the ratings
of the circulation pump and its intended use.
The following clauses of IEC 61984:2008 and the corresponding test requirements in Clause 7,
are not applicable: 5.2 a), 5.4 d), 6.2.1, 6.2.2, 6.4.1, 6.4.2, 6.4.3, 6.10, 6.14.2, 6.14.3, 6.17,
6.19 and 6.20. Subclause 6.5.1 is also applicable for connectors without breaking capacity
(COC). Subclauses 6.15 and 6.16 are applicable but are modified to the circulation pump tem-
perature ratings. The tests in 7.3.6, 7.3.7 are performed when the connector referenced in
22.102 is engaged.
25 Supply connection and external flexible cords
This clause of Part 1 is applicable except as follows.
25.3 Addition of the following Note after the first dashed item:
NOTE 101 The set of terminals can be located in a separate connector complying with 24.1.101.
25.5 Addition:
Type Z attachment is allowed.
26 Terminals for external conductors
This clause of Part 1 is applicable.
27 Provision for earthing
This clause of Part 1 is applicable.
28 Screws and connections
This clause of Part 1 is applicable.
29 Clearances, creepage distances and solid insulation
This clause of Part 1 is applicable.
30 Resistance to heat and fire
This clause of Part 1 is applicable except as follows.
30.2.2 Not applicable.
31 Resistance to rusting
This clause of Part 1 is applicable.
32 Radiation, toxicity and similar hazards
This clause of Part 1 is applicable.
– 14 – IEC 60335-2-51:2023 © IEC 2023
Annexes
The annexes of Part 1 are applicable except as follows.
Annex A
(informative)
Routine tests
A.3 Electric strength test
Addition:
For appliances with a high leakage current, the value of 30 mA is increased to 70 mA.
Bibliography
The bibliography of Part 1 is applicable except as follows.
Addition:
IEC 60335-2-41, Household and similar electrical appliances – Safety – Part 2-41: Particular
requirements for pumps
___________
– 16 – IEC 60335-2-51:2023 © IEC 2023
SOMMAIRE
AVANT-PROPOS . 17
INTRODUCTION . 20
1 Domaine d'application . 21
2 Références normatives . 22
3 Termes et définitions . 22
4 Exigences générales . 22
5 Conditions générales d'essais . 22
6 Classification . 22
7 Marquage et instructions . 23
8 Protection contre l'accès aux parties actives. 24
9 Démarrage des appareils à moteur . 24
10 Puissance et courant . 24
11 Échauffements. 24
12 Charge des batteries à ions métalliques . 25
13 Courant de fuite et rigidité diélectrique à la température de régime . 25
14 Surtensions transitoires . 25
15 Résistance à l'humidité . 25
16 Courant de fuite et rigidité diélectrique . 25
17 Protection contre la surcharge des transformateurs et des circuits associés . 25
18 Endurance . 25
19 Fonctionnement anormal . 25
20 Stabilité et dangers mécaniques . 26
21 Résistance mécanique . 26
22 Construction . 26
23 Conducteurs internes. 26
24 Composants . 26
25 Raccordement au réseau et câbles souples extérieurs . 27
26 Bornes pour conducteurs externes . 27
27 Dispositions en vue de la mise à la terre . 27
28 Vis et connexions . 27
29 Distances dans l'air, lignes de fuite et isolation solide. 27
30 Résistance à la chaleur et au feu . 28
31 Protection contre la rouille . 28
32 Rayonnement, toxicité et dangers analogues . 28
Annexes . 29
Annexe A (informative) Essais individuels de série . 29
Bibliographie . 30
Tableau 101 – Classification des températures des pompes de circulation. 23
COMMISSION ÉLECTROTECHNIQUE INTERNATIONALE
____________
APPAREILS ÉLECTRODOMESTIQUES ET ANALOGUES –
SÉCURITÉ –
Partie 2-51: Exigences particulières pour les pompes de circulation fixes
pour installations de chauffage et de distribution d'eau
AVANT-PROPOS
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de l'ensemble des comités électrotechniques nationaux (Comités nationaux de l'IEC). L'IEC a pour objet de
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