IEC 60335-2-73:2024

Household and similar electrical appliances - Safety - Part 2-73: Particular requirements for fixed immersion heaters

IEC 60335-2-73:2024 deals with the safety of fixed electric immersion heaters for household and similar purposes that are intended for installation in a water tank open to the atmosphere for heating water to a temperature below its boiling point with a rated voltage of not more than 250 V for single-phase appliances and 480 V for other appliances including direct current (DC) supplied appliances. The water tank can have alternative means for heating water, such as the circulation of hot water supplied from a separate boiler. Immersion heaters having a rated power input up to 25 kW for incorporation as an alternative heating source in central heating boilers are also within the scope of this standard. Appliances not intended for normal household use but which nevertheless can be a source of danger to the public, such as appliances intended to be used by laypersons 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, the national water supply authorities and similar authorities.
This standard does not apply to
appliances intended exclusively for industrial purposes;
- appliances intended to be used in locations where special conditions prevail, such as the presence of a corrosive or explosive atmosphere (dust, vapour or gas);
- heating elements incorporated in appliances such as appliances for heating liquids (IEC 60335-2-15), storage water heaters (IEC 60335-2-21) and instantaneous water heaters (IEC 60335-2-35);
- aquarium heaters (IEC 60335-2-55);
- portable immersion heaters (IEC 60335-2-74);
- engine preheaters such as those for cars and buses.
This third edition cancels and replaces the second edition published in 2002, Amendment 1: 2006 and Amendment 2: 2009. 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, 19.2);
c) addition of external accessible surface temperatures (Clause 11);
This part 2 is to be used in conjunction with the latest edition of IEC 60335-1:2020 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 2-73: Règles particulières pour les thermoplongeurs installés à poste fixe

L’IEC 60335-2-73:2024 traite de la sécurité des thermoplongeurs électriques installés à poste fixe à usages domestiques et analogues, destinés à être installés dans une cuve ouverte à l'air libre, pour chauffer de l’eau à une température inférieure à l’ébullition, 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. La cuve peut comporter d'autres moyens pour chauffer l'eau tels qu'une circulation d'eau chaude fournie par une chaudière séparée. Les thermoplongeurs de puissance assignée jusqu'à 25 kW destinés à être incorporés comme source alternative de chaleur dans des chaudières de chauffage central font également partie du domaine d'application de la présente norme. Les appareils non destinés à un usage domestique normal mais qui, néanmoins, peuvent 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 les 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;
- de l’utilisation de l’appareil comme jouet par des enfants.
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'aéronefs, 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, par les organismes nationaux responsables de l'alimentation en eau et par des organismes similaires.
La présente norme ne s’applique pas
- aux appareils destinés exclusivement à des usages industriels;
- aux appareils destinés à être utilisés dans des locaux présentant des conditions particulières, telles que la présence d’une atmosphère corrosive ou explosive (poussière, vapeur ou gaz);
- aux éléments chauffants incorporés dans des appareils tels que les appareils de chauffage des liquides (IEC 60335-2-15), les chauffe-eau à accumulation (IEC 60335-2-21) ou les chauffe-eau instantanés (IEC 60335-2-35);
- aux appareils de chauffage des aquariums (IEC 60335-2-55);
- aux thermoplongeurs mobiles (IEC 60335-2-74);
- aux dispositifs de préchauffage des moteurs tels que ceux des voitures et autocars.
Cette troisième édition annule et remplace la deuxième édition parue en 2002, son Amendement 1: 2006 et son Amendement 2: 2009. 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 transformées en texte normatif (Article 1, 19.2);
c) ajout des températures des surfaces accessibles extérieures (Article 11).
La présente partie 2 doit être utilisée conjointement avec la dernière édition de l'IEC IEC 60335-1:2020 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.

General Information

• Status: Published
• Publication Date: 13-Mar-2024
• ICS: 91.140.65 - Water heating equipment
• Technical Committee: TC 61 - Safety of household and similar electrical appliances
• Drafting Committee: MT 37 - TC 61/MT 37
• Current Stage: PPUB - Publication issued
• Start Date: 10-Apr-2024
• Completion Date: 14-Mar-2024

Relations

• Revises: IEC 60335-2-73:2002 - Household and similar electrical appliances - Safety - Part 2-73: Particular requirements for fixed immersion heaters
• Effective Date: 05-Sep-2023
• Revises: IEC 60335-2-73:2002/AMD1:2006 - Amendment 1 - Household and similar electrical appliances - Safety - Part 2-73: Particular requirements for fixed immersion heaters
• Effective Date: 05-Sep-2023
• Revises: IEC 60335-2-73:2002/AMD2:2009 - Amendment 2 - Household and similar electrical appliances - Safety - Part 2-73: Particular requirements for fixed immersion heaters
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 60335-2-73 ®
Edition 3.0 2024-03
COMMENTED VERSION
INTERNATIONAL
STANDARD
colour
inside
Household and similar electrical appliances – Safety –
Part 2-73: Particular requirements for fixed immersion heaters
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
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IEC 60335-2-73 ®
Edition 3.0 2024-03
COMMENTED VERSION
INTERNATIONAL
STANDARD
colour
inside
Household and similar electrical appliances – Safety –
Part 2-73: Particular requirements for fixed immersion heaters
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 91.140.65 ISBN 978-2-8322-8546-6
– 2 – IEC 60335-2-73:2024 CMV © IEC 2024
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 .9
9 Starting of motor-operated appliances .9
10 Power input and current .9
11 Heating .9
12 Charging of metal-ion batteries . 10
13 Leakage current and electric strength at operating temperature . 10
14 Transient overvoltages . 10
15 Moisture resistance . 10
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 . 11
21 Mechanical strength . 11
22 Construction . 11
23 Internal wiring . 12
24 Components . 12
25 Supply connection and external flexible cords . 12
26 Terminals for external conductors . 12
27 Provision for earthing . 12
28 Screws and connections . 12
29 Clearances, creepage distances and solid insulation . 12
30 Resistance to heat and fire . 12
31 Resistance to rusting. 13
32 Radiation, toxicity and similar hazards . 13
Annexes . 14
Bibliography . 15
List of comments . 16

Figure 101 – Probe for measuring surface temperatures . 13

Table 101 – Maximum temperature rises for specified external accessible surfaces
under normal operating conditions . 10

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
SAFETY –
Part 2-73: Particular requirements for fixed immersion heaters

FOREWORD
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This commented version (CMV) of the official standard IEC 60335-2-73:2024 edition 3.0
allows the user to identify the changes made to the previous IEC 60335-2-73:
2002+AMD1:2006+AMD2:2009 CSV edition 2.2. 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
comment.
This publication contains the CMV and the official standard. The full list of comments is
available at the end of the CMV.

– 4 – IEC 60335-2-73:2024 CMV © IEC 2024
IEC 60335-2-73 has been prepared by IEC technical committee 61: Safety of household and
similar electrical appliances. It is an International Standard.
This third edition cancels and replaces the second edition published in 2002, Amendment 1:
2006 and Amendment 2: 2009. 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, 19.2);
c) addition of external accessible surface temperatures (Clause 11).
The text of this International Standard is based on the following documents:
Draft Report on voting
61/6954/CDV 61/7055A/RVC
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 6033
...

IEC 60335-2-73 ®
Edition 3.0 2024-03
EXTENDED VERSION
INTERNATIONAL
STANDARD
colour
inside
This extended version of IEC 60335-2-73:2024 includes the content of the references made to
IEC 60335-1:2020
Household and similar electrical appliances – Safety –
Part 2-73: Particular requirements for fixed immersion heaters
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
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copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
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IEC 60335-2-73 ®
Edition 3.0 2024-03
EXTENDED VERSION
INTERNATIONAL
STANDARD
colour
inside
This extended version of IEC 60335-2-73:2024 includes the content of the references made to
IEC 60335-1:2020
Household and similar electrical appliances – Safety –
Part 2-73: Particular requirements for fixed immersion heaters
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 01.140.65 ISBN 978-2-8322-8548-0

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 60335-2-73:2024 EXV © IEC 2024
CONTENTS
FOREWORD . 6
INTRODUCTION . 9
1 Scope . 10
2 Normative references . 11
3 Terms and definitions . 16
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 . 45
12 Charging of metal-ion batteries . 51
13 Leakage current and electric strength at operating temperature . 52
14 Transient overvoltages . 55
15 Moisture resistance . 56
16 Leakage current and electric strength . 58
17 Overload protection of transformers and associated circuits . 60
18 Endurance . 61
19 Abnormal operation . 61
20 Stability and mechanical hazards . 71
21 Mechanical strength . 72
22 Construction . 74
23 Internal wiring . 87
24 Components . 89
25 Supply connection and external flexible cords . 94
26 Terminals for external conductors . 102
27 Provision for earthing . 104
28 Screws and connections . 106
29 Clearances, creepage distances and solid insulation . 109
30 Resistance to heat and fire . 118
31 Resistance to rusting . 121
32 Radiation, toxicity and similar hazards . 122
Annex A (informative) Routine tests . 137
Annex B (normative) Battery-operated appliances, separable batteries and detachable
batteries for battery-operated appliances . 139
Annex C (normative) Ageing test on motors . 160
Annex D (normative) Thermal motor protectors . 161
Annex E (normative) Needle-flame test . 162
Annex F (normative) Capacitors . 163
Annex G (normative) Safety isolating transformers . 165

Annex H (normative) Switches . 166
Annex I (normative) Motors having basic insulation that is inadequate for the rated
voltage of the appliance . 168
Annex J (normative) Coated printed circuit boards . 170
Annex K (informative) Overvoltage categories . 171
Annex L (informative) Guidance for the measurement of clearances and creepage
distances . 172
Annex M (informative) Pollution degree . 175
Annex N (normative) Proof tracking test . 176
Annex O (informative) Selection and sequence of the tests of Clause 30 . 177
Annex P (informative) Guidance for the application of this standard to appliances
used in tropical climates . 182
Annex Q (informative) Sequence of tests for the evaluation of electronic circuits . 184
Annex R (normative) Software evaluation . 187
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 . 201
Annex T (normative) UV-C radiation effect on non-metallic materials . 202
Annex U (normative) Appliances intended for remote communication through public
networks . 205
Bibliography . 209
Index of defined terms . 212

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 . 123
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 . 124
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 . 125
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 . 126
Figure 5 – Small part . 127
Figure 6 – Example of an electronic circuit with low-power points . 127
Figure 7 – Test finger nail . 128
Figure 8 – Flexing test apparatus . 129
Figure 9 – Constructions of cord anchorages . 130
Figure 10 – An example of parts of an earthing terminal . 131
Figure 11 – Examples of clearances . 132
Figure 12 – Example of the placement of the cylinder .
...

IEC 60335-2-73 ®
Edition 3.0 2024-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Household and similar electrical appliances – Safety –
Part 2-73: Particular requirements for fixed immersion heaters

Appareils électrodomestiques et analogues – Sécurité –
Partie 2-73: Règles particulières pour les thermoplongeurs installés à poste fixe
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International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
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IEC 60335-2-73 ®
Edition 3.0 2024-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Household and similar electrical appliances – Safety –

Part 2-73: Particular requirements for fixed immersion heaters

Appareils électrodomestiques et analogues – Sécurité –

Partie 2-73: Règles particulières pour les thermoplongeurs installés à poste fixe

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 91.140.65  ISBN 978-2-8322-8459-9

– 2 – IEC 60335-2-73:2024 © IEC 2024
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 . 9
9 Starting of motor-operated appliances . 9
10 Power input and current . 9
11 Heating . 9
12 Charging of metal-ion batteries . 10
13 Leakage current and electric strength at operating temperature . 10
14 Transient overvoltages . 10
15 Moisture resistance . 10
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 . 11
21 Mechanical strength . 11
22 Construction . 11
23 Internal wiring . 12
24 Components . 12
25 Supply connection and external flexible cords . 12
26 Terminals for external conductors . 12
27 Provision for earthing . 12
28 Screws and connections . 12
29 Clearances, creepage distances and solid insulation . 12
30 Resistance to heat and fire . 12
31 Resistance to rusting . 13
32 Radiation, toxicity and similar hazards . 13
Annexes . 14
Bibliography . 15

Figure 101 – Probe for measuring surface temperatures . 13

Table 101 – Maximum temperature rises for specified external accessible surfaces
under normal operating conditions . 10

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
SAFETY –
Part 2-73: Particular requirements for fixed immersion heaters

FOREWORD
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