Thermal energy meters - Part 1: General requirements

This document is applicable for the general requirements for thermal energy meters. Thermal energy meters are instruments intended for measuring the energy which in a heat-exchange circuit is absorbed (cooling) or given up (heating) by a liquid called the heat-conveying liquid. The thermal energy meter indicates the quantity of thermal energy in legal units.
This document covers meters for closed systems only, where the differential pressure over the thermal load is limited.
This document is not applicable to:
-   electrical safety requirements;
-   pressure safety requirements; and
-   surface mounted temperature sensors.

Thermische Energiemessgeräte - Teil 1: Allgemeine Anforderungen

Dieses Dokument legt die allgemeinen Anforderungen für thermische Energiemessgeräte fest. Thermische Energiemessgeräte sind Messgeräte, die dazu bestimmt sind, die Energie zu messen, die in einem Wärmetauschkreislauf von einer als Wärmeträgerflüssigkeit bezeichneten Flüssigkeit aufgenommen (Kühlung) oder abgegeben (Heizung) wird. Das thermische Energiemessgerät zeigt die Menge der thermischen Energie in gesetzlichen Einheiten an.
Anforderungen an die elektrische Sicherheit sind nicht Gegenstand dieses Dokuments.
Anforderungen an die Drucksicherheit sind nicht Gegenstand dieses Dokuments.
Oberflächenmontierte Temperaturfühler sind nicht Gegenstand dieses Dokuments.
Dieses Dokument behandelt nur Messgeräte für geschlossene Systeme, bei denen der Differenzdruck über die thermische Last begrenzt ist.

Compteurs d'énergie thermique - Partie 1 : Prescriptions générales

Le présent document est applicable aux prescriptions générales relatives aux compteurs d’énergie thermique. Les compteurs d’énergie thermique sont des instruments destinés à mesurer l’énergie thermique qui, dans un circuit d’échange thermique, est absorbée (refroidissement) ou cédée (chauffage) par un liquide appelé « liquide caloporteur ». Le compteur d’énergie thermique fournit la quantité d’énergie thermique en unités de mesure légales.
Le présent document couvre les compteurs pour les systèmes fermés uniquement, où la pression différentielle dans la charge thermique est limitée.
Le présent document ne s’applique pas :
-   aux prescriptions de sécurité électrique ;
-   aux prescriptions de sécurité relatives à la pression ; ni
-   aux sondes de température montées en surface.

Merilniki toplote - 1. del: Splošne zahteve

General Information

Status
Published
Current Stage
6060 - Definitive text made available (DAV) - Publishing
Due Date
12-Feb-2020

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SLOVENSKI STANDARD
SIST EN 1434-1:2022
01-november-2022
Nadomešča:
SIST EN 1434-1:2016+A1:2019
Merilniki toplote - 1. del: Splošne zahteve
Thermal energy meters - Part 1: General requirements
Thermische Energiemessgeräte - Teil 1: Allgemeine Anforderungen
Compteurs d'énergie thermique - Partie 1 : Prescriptions générales
Ta slovenski standard je istoveten z: EN 1434-1:2022
ICS:
17.200.20 Instrumenti za merjenje Temperature-measuring
temperature instruments
SIST EN 1434-1:2022 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST EN 1434-1:2022
---------------------- Page: 2 ----------------------
SIST EN 1434-1:2022
EN 1434-1
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2022
EUROPÄISCHE NORM
ICS 17.200.20 Supersedes EN 1434-1:2015+A1:2018
English Version
Thermal energy meters - Part 1: General requirements

Compteurs d'énergie thermique - Partie 1 : Thermische Energiemessgeräte - Teil 1: Allgemeine

Prescriptions générales Anforderungen
This European Standard was approved by CEN on 17 July 2022.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this

European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references

concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN

member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by

translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management

Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,

Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and

United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 1434-1:2022 E

worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN 1434-1:2022
EN 1434-1:2022 (E)
Contents Page

European foreword ...................................................................................................................................................... 4

1 Scope .................................................................................................................................................................... 6

2 Normative references .................................................................................................................................... 6

3 Terms and definitions ................................................................................................................................... 6

4 Types of instruments ................................................................................................................................... 12

4.1 General.............................................................................................................................................................. 12

4.2 Complete instrument ................................................................................................................................... 12

4.3 Combined instrument ................................................................................................................................. 12

4.4 Hybrid instrument ........................................................................................................................................ 12

4.5 Sub-assemblies of a thermal energy meter, which is a combined instrument ....................... 12

4.5.1 General.............................................................................................................................................................. 12

4.5.2 Flow sensor ..................................................................................................................................................... 12

4.5.3 Temperature sensor pair ........................................................................................................................... 12

4.5.4 Calculator ......................................................................................................................................................... 12

4.6 Equipment under test (EUT) ..................................................................................................................... 13

5 Rated operating conditions ....................................................................................................................... 13

5.1 Limits of temperature range ..................................................................................................................... 13

5.2 Limits of temperature differences .......................................................................................................... 13

5.3 Limits of flow rate ......................................................................................................................................... 13

5.4 Limit of thermal power ............................................................................................................................... 13

5.5 Limits of working pressure (PS and P ) ............................................................................................. 14

min

5.6 Nominal pressure (PN) ............................................................................................................................... 14

5.7 Limits in ambient temperature ............................................................................................................... 14

5.8 Limits in deviations in supply voltage ................................................................................................... 14

5.9 Maximum pressure loss .............................................................................................................................. 14

5.10 Specific requirements on registration devices .................................................................................. 14

5.10.1 General.............................................................................................................................................................. 14

5.10.2 Suitability ......................................................................................................................................................... 14

5.10.3 Rated operated conditions ........................................................................................................................ 15

5.10.4 Indication ......................................................................................................................................................... 15

5.10.5 MPE for additional functionalities (smart metering functionality) ........................................... 16

6 Technical characteristics ........................................................................................................................... 16

6.1 Materials and construction ....................................................................................................................... 16

6.2 Requirements outside the limiting values of the flow rate ........................................................... 17

6.3 Display .............................................................................................................................................................. 17

6.4 Protection against fraud ............................................................................................................................. 18

6.5 Supply voltage ................................................................................................................................................ 18

6.6 Effect on temperature sensor pairs by mounting in pockets ........................................................ 18

6.7 Reproducibility .............................................................................................................................................. 18

6.8 Repeatability .................................................................................................................................................. 19

6.9 Software ........................................................................................................................................................... 19

7 Specified working range ............................................................................................................................. 19

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SIST EN 1434-1:2022
EN 1434-1:2022 (E)

7.1 General ............................................................................................................................................................. 19

7.2 Temperature difference ............................................................................................................................. 19

7.3 Flow rate .......................................................................................................................................................... 19

8 Heat transmission formula ....................................................................................................................... 19

9 Metrological characteristics (Maximum Permissible Error, MPE) ............................................. 20

9.1 General ............................................................................................................................................................. 20

9.2 Values of maximum permissible errors ............................................................................................... 20

9.2.1 Maximum permissible relative errors of complete thermal energy meters........................... 20

9.2.2 Maximum permissible relative error of sub-assemblies ............................................................... 21

9.3 Application of maximum permissible errors ..................................................................................... 21

10 Environmental classification .................................................................................................................... 22

10.1 General ............................................................................................................................................................. 22

10.2 Environmental class A (Domestic use, indoor installations) ........................................................ 22

10.3 Environmental class B (Domestic use, outdoor installations) ..................................................... 22

10.4 Environmental class C (Industrial installations) .............................................................................. 22

10.5 Mechanical classes M1 to M3 .................................................................................................................... 22

11 Thermal energy meter specification ..................................................................................................... 23

11.1 General ............................................................................................................................................................. 23

11.2 Flow sensor ..................................................................................................................................................... 23

11.3 Temperature sensor pair ........................................................................................................................... 24

11.4 Calculator ........................................................................................................................................................ 25

11.5 Complete meters ........................................................................................................................................... 26

12 Information to be made available by the manufacturer or supplier ......................................... 28

12.1 Installation instructions ............................................................................................................................. 28

12.2 Parameter setting instructions................................................................................................................ 29

12.3 Adjustment instructions ............................................................................................................................ 30

12.4 Maintenance instructions .......................................................................................................................... 30

12.5 Information required when a thermal energy meter is taken out of service for

recycling and/or disposal .......................................................................................................................... 31

12.5.1 General ............................................................................................................................................................. 31

12.5.2 Disassembly .................................................................................................................................................... 31

12.5.3 Recycling .......................................................................................................................................................... 31

12.5.4 Disposal ............................................................................................................................................................ 31

Annex A (normative) Heat coefficient formulae ............................................................................................. 32

A.1 Water ................................................................................................................................................................. 32

A.2 Heat-conveying liquids other than water ............................................................................................ 34

Annex B (normative) Flow conditioner package ............................................................................................ 35

Annex C (normative) Fast response meters ..................................................................................................... 37

Annex ZA (informative) Relationship between this European Standard and the essential

requirements of Directive 2014/32/EU aimed to be covered ..................................................... 38

Bibliography ................................................................................................................................................................. 42

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SIST EN 1434-1:2022
EN 1434-1:2022 (E)
European foreword

This document (EN 1434-1:2022) has been prepared by Technical Committee CEN/TC 176 “Thermal

energy meters”, the secretariat of which is held by SIS.

This European Standard shall be given the status of a national standard, either by publication of an

identical text or by endorsement, at the latest by March 2023, and conflicting national standards shall

be withdrawn at the latest by March 2023.

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CEN shall not be held responsible for identifying any or all such patent rights.

This document supersedes EN 1434-1:2015+A1:2018.
EN 1434, Thermal energy meters, consists of the following parts:
— Part 1: General requirements;
— Part 2: Constructional requirements;
— Part 3: Data exchange and interfaces ;
— Part 4: Pattern approval tests;
— Part 5: Initial verification tests;
— Part 6: Installation, commissioning, operational monitoring and maintenance.
In comparison with EN 1434-1:2015+A1:2018, the following changes have been made:

— the wording “flow straightener” has been changed to “flow conditioner” in the whole document;

— subclause 12.5 “Hints for disposal instructions” has been replaced by the enlarged, new

subclause 12.5 “Information required when a thermal energy meter is taken out of service for

recycling and/or disposal”.

This document has been prepared under a Standardization Request given to CEN by the European

Commission and the European Free Trade Association, and supports essential requirements of EU

Directive(s) / Regulation(s).

For relationship with EU Directive(s) / Regulation(s), see informative Annex ZA, which is an integral

part of this document.

Any feedback and questions on this document should be directed to the users’ national standards body.

A complete listing of these bodies can be found on the CEN website.

According to the CEN-CENELEC Internal Regulations, the national standards organisations of the

following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,

Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,

Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of

EN 1434-3 is maintained by CEN/TC 294.
---------------------- Page: 6 ----------------------
SIST EN 1434-1:2022
EN 1434-1:2022 (E)

North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the

United Kingdom.
---------------------- Page: 7 ----------------------
SIST EN 1434-1:2022
EN 1434-1:2022 (E)
1 Scope

This document is applicable for the general requirements for thermal energy meters. Thermal energy

meters are instruments intended for measuring the energy which in a heat-exchange circuit is absorbed

(cooling) or given up (heating) by a liquid called the heat-conveying liquid. The thermal energy meter

indicates the quantity of thermal energy in legal units.

This document covers meters for closed systems only, where the differential pressure over the thermal

load is limited.
This document is not applicable to:
— electrical safety requirements;
— pressure safety requirements; and
— surface mounted temperature sensors.
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.

EN 1434-2:2022, Thermal energy meters — Part 2: Constructional requirements
EN 1434-4:2022, Thermal energy meters — Part 4: Pattern approval tests

EN 60751:2008, Industrial platinum resistance thermometers and platinum temperature sensors

(IEC 60751:2008)

EN 61010-1:2010, Safety requirements for electrical equipment for measurement, control and laboratory

use — Part 1: General requirements (IEC 61010-1:2010)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— IEC Electropedia: available at https://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp
3.1
response time
0,5

time interval between the instant when flow or temperature difference is subjected to a specified

abrupt change and the instant when the response reaches 50 % of the step value
3.2
fast response meter

meter suitable for heat exchanging circuits with rapid dynamic variations in the exchanged heat

Note 1 to entry: See also Annex C.
Document is impacted by /A1:2019 and /A1:2019/AC:2019-04.
---------------------- Page: 8 ----------------------
SIST EN 1434-1:2022
EN 1434-1:2022 (E)
3.3
rated voltage

voltage of the external power supply required to operate the thermal energy meter, conventionally the

voltage of the AC mains supply
3.4
rated operating conditions

conditions of use, giving the range of values of influence quantities, for which the metrological

characteristics of the instrument are within the specified maximum permissible errors

3.5
reference conditions

set of specified values of influence factors, fixed to ensure valid inter-comparison of results of

measurements
3.6
influence quantity

quantity, which is not the subject of the measurement, but which influences the value of the

measurement and or the indication of the measuring instrument
3.7
influence factor
influence quantity having a value within the rated operating conditions
3.8
disturbance
influence quantity having a value outside the rated operating conditions
3.9
types of errors
3.9.1
error of indication

indication of the measuring instrument minus the conventional true value of the measurand

3.9.2
intrinsic error
error of a measuring instrument determined under reference conditions
3.9.3
initial intrinsic error

error of a measuring instrument as determined once prior to performance tests and durability tests

3.9.4
durability error

difference between the intrinsic error after a period of use and the initial intrinsic error

3.9.5
maximum permissible error
MPE
highest values of the error (positive or negative) permitted
---------------------- Page: 9 ----------------------
SIST EN 1434-1:2022
EN 1434-1:2022 (E)
3.10
types of faults
3.10.1
fault

difference between the error of indication and the intrinsic error of the instrument

3.10.2
transitory fault

momentary variations in the indication, which cannot be interpreted, memorized or transmitted as

measurements
3.10.3
significant fault

fault greater than the absolute value of the MPE and not being a transitory fault

Note 1 to entry: If the MPE is ± 2 % then the significant fault is a fault larger than ± 2 %.

3.11
reference values of the measurand
RVM

specified value of the flow rate, the outlet temperature and the temperature difference, fixed to ensure

valid intercomparison of the results of measurements
3.12
conventional true value
quantity value attributed by agreement to a quantity for a given purpose

Note 1 to entry: A conventional true value is, in general, regarded as sufficiently close to the true value for the

difference to be insignificant for the given purpose.
EXAMPLE A true value is the heat coefficient according to Annex A.
3.13
meter model

different sizes of thermal energy meters or sub-assemblies having a family similarity in the principles of

operation, construction and materials
3.14
electronic device
device employing electronic elements and performing a specific function
3.15
electronic element

smallest physical entity in an electronic device which uses electron hole conduction in semi-conductors,

or electron conduction in gases or in a vacuum
3.16
qualifying immersion depth of a temperature sensor

immersion depth over which the sensor measures with an accurate temperature value

Note 1 to entry: The conditions to define the qualified immersion depth are written in EN 1434-4:2022, 7.4.4.1.

---------------------- Page: 10 ----------------------
SIST EN 1434-1:2022
EN 1434-1:2022 (E)
3.17
self-heating effect

increase in temperature signal that is obtained by subjecting each temperature sensor of a pair to a

continuous power dissipation of 5 mW when immersed to the qualifying immersion depth in a water

bath, having a mean water velocity of 0,1 m/s
3.18
thermal energy meter

instrument intended for measuring the energy which in a heat-exchange circuit is absorbed (cooling) or

given up (heating) by a liquid called the heat-conveying liquid
3.19
meters other than for heating
3.19.1
cooling meter

thermal energy meter designed for cooling applications at low temperatures, normally covering the

temperature range 2 °C to 30 °C and ΔΘ up to 20 K
3.19.2
bifunctional meters for change-over systems between heating and cooling
instrument measuring heating and cooling energy in two separate registers

Note 1 to entry: The functionality of the bifunctional meter is described in Figure 1 as an example.

Note 2 to entry: In other directives and requirements, bifunctional meters are called combined meters.

Key
No energy recording
Heating
Cooling
θInlet temperature of the inlet respectively outlet
θ switching temperature for heating/cooling (e.g. 25 °C)
ΔΘ starting temperature difference of energy accumulation (e.g. 0,1 K)
ΔΘmin minimum approved temperature difference (e.g. 3 K)
Figure 1 — Example for function of heating and cooling register
---------------------- Page: 11 ----------------------
SIST EN 1434-1:2022
EN 1434-1:2022 (E)
3.20
flow direction
direction of the liquid going through the system from inlet to outlet

Note 1 to entry: The inlet is for the heating case the hot side and for the cooling case the cold side.

Note 2 to entry: In the literature the word “flow” is also being used for “inlet”, and the word “return” is also being

used for “outlet”.

Note 3 to entry: Different temperature values for θ for heating and cooling applications may also occur.

3.21
electrical pulse

electrical signal (voltage, current or change in resistance), that departs from an initial level for a limited

duration of time and ultimately returns to the original level
3.22
pulse output and input devices
3.22.1
pulse output device
functional part of flow sensor, calculator or auxiliary devices
EXAMPLE Remote displays or input devices of control systems.
3.22.2
pulse input device
functional part of flow sensor, calculator or auxiliary devices
EXAMPLE Pulse input for external water meter.
3.23
maximum admissible temperature

maximum temperature of the heat conveying liquid the meter can withstand in combination with the

maximum admissible working pressure and the permanent flow rate for short periods of time

(< 1 h/day; < 200 h/year) without a significant fault after the exposure to this maximum admissible

temperature
3.24
durability

characteristic of a measuring instrument to keep the metrological characteristics over time (e.g. to fulfil

the double of MPE), provided that it is properly installed, maintained and used within the permissible

environmental conditions
3.25
long life flow sensor

flow sensor designed to have a longer lifetime than a normal flow sensor, which typically has a

durability of 5 years under the specified operating conditions
3.26
user interface

interface forming part of the instrument that enables information to be passed between a human user

and the measuring instrument or its components (e.g. display)
---------------------- Page: 12 ----------------------
SIST EN 1434-1:2022
EN 1434-1:2022 (E)
3.27
communication interface

electronic, optical, radio or other technical interface that enables information via correct transceiving of

at least thermal energy to be passed between measuring instruments, sub-assemblies or external

devices
3.28
meter for smart metering

thermal energy meter with the capability of data communication and support of smart metering

functionalities

Note 1 to entry: Data could be transmitted via user interface and/ or communication interface in fixed time

intervals and/or on request.

Note 2 to entry: For more information on smart meters, see standard series EN 13757 and

CEN/CLC/ETSI TR 50572.
3.29
registration device

optional additional device fitted to the meter as an integral part or separate device, in order to register

the amount of thermal energy accumulated in additional registers during periods, depending on

conditions, e. g. flow rate, inlet or outlet temperatures, temperature differences or time points

3.30
register

component of a registration device which contains accumulated or actual values e. g. thermal energy,

volume, maximum flow rate, power or temperature
3.31
interval register

register which contains frequently accumulated or copied values used for registration of billing

purposes and/ or for controlling processes

Note 1 to entry: During consecutive time intervals values could be achieved by copying from an accumulating

main register which contains actual values of e.g. thermal energy or volume.

Note 2 to entry: During consecutive time intervals the measured process values of flow rate and/or temperature

could be additionally stored.
3.32
maximum flow
highest rate of flow which is expected at operating conditions
Note 1 to entry: For the limits of flow rates, see 5.3.
---------------------- Page: 13 ----------------------
SIST EN 1434-1:2022
EN 1434-1:2022 (E)
3.33

heat-conveying liquids other than water (mixed fluids, e.g. water glycol mixtures)

mixture of water with a defined proportion of another fluid e.g. mono-ethylene or propylene glycol

Note 1 to entry: Typical heat conveying liquids on the market consist of a base liquid (e.g. water with propylene

glycol) and additives to prevent corrosion or counteract chemical reactions like acid formation. The liquids often

differ in their constitution
...

SLOVENSKI STANDARD
oSIST prEN 1434-1:2020
01-november-2020
Merilniki toplote - 1. del: Splošne zahteve
Thermal energy meters - Part 1: General requirements
Thermische Energiemessgeräte - Teil 1: Allgemeine Anforderungen
Compteurs d'énergie thermique - Partie 1 : Prescriptions générales
Ta slovenski standard je istoveten z: prEN 1434-1
ICS:
17.200.20 Instrumenti za merjenje Temperature-measuring
temperature instruments
oSIST prEN 1434-1:2020 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
oSIST prEN 1434-1:2020
---------------------- Page: 2 ----------------------
oSIST prEN 1434-1:2020
DRAFT
EUROPEAN STANDARD
prEN 1434-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
November 2020
ICS 17.200.20 Will supersede EN 1434-1:2015+A1:2018
English Version
Thermal energy meters - Part 1: General requirements

Compteurs d'énergie thermique - Partie 1 : Thermische Energiemessgeräte - Teil 1: Allgemeine

Prescriptions générales Anforderungen

This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee

CEN/TC 176.

If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations

which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other

language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC

Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,

Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and

United Kingdom.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are

aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without

notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 1434-1:2020 E

worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
oSIST prEN 1434-1:2020
prEN 1434-1:2020 (E)
Contents Page

European foreword ............................................................................................................................................ 4

1 Scope .......................................................................................................................................................... 5

2 Normative references .......................................................................................................................... 5

3 Terms and definitions ......................................................................................................................... 5

4 Types of instruments ......................................................................................................................... 11

4.1 General.................................................................................................................................................... 11

4.2 Complete instrument ......................................................................................................................... 11

4.3 Combined instrument ....................................................................................................................... 11

4.4 Hybrid instrument .............................................................................................................................. 11

4.5 Sub-assemblies of a thermal energy meter, which is a combined instrument ............. 11

4.5.1 General.................................................................................................................................................... 11

4.5.2 Flow sensor ........................................................................................................................................... 11

4.5.3 Temperature sensor pair ................................................................................................................. 11

4.5.4 Calculator ............................................................................................................................................... 11

4.6 Equipment under test (EUT) ........................................................................................................... 11

5 Rated operating conditions ............................................................................................................. 11

5.1 Limits of temperature range ........................................................................................................... 11

5.2 Limits of temperature differences ................................................................................................ 12

5.3 Limits of flow rate ............................................................................................................................... 12

5.4 Limit of thermal power ..................................................................................................................... 12

5.5 Limits of working pressure (PS and P ) ................................................................................. 12

min

5.6 Nominal pressure (PN) ..................................................................................................................... 13

5.7 Limits in ambient temperature ..................................................................................................... 13

5.8 Limits in deviations in supply voltage ......................................................................................... 13

5.9 Maximum pressure loss .................................................................................................................... 13

5.10 Specific requirements on registration devices ........................................................................ 13

5.10.1 General.................................................................................................................................................... 13

5.10.2 Suitability ............................................................................................................................................... 13

5.10.3 Rated operated conditions .............................................................................................................. 14

5.10.4 Indication ............................................................................................................................................... 14

5.10.5 MPE for additional functionalities (smart metering functionality) ................................. 15

6 Technical characteristics ................................................................................................................. 15

6.1 Materials and construction ............................................................................................................. 15

6.2 Requirements outside the limiting values of the flow rate ................................................. 16

6.3 Display .................................................................................................................................................... 16

6.4 Protection against fraud ................................................................................................................... 17

6.5 Supply voltage ...................................................................................................................................... 17

6.6 Effect on temperature sensor pairs by mounting in pockets .............................................. 17

6.7 Reproducibility .................................................................................................................................... 17

6.8 Repeatability ........................................................................................................................................ 18

6.9 Software ................................................................................................................................................. 18

7 Specified working range ................................................................................................................... 18

7.1 General.................................................................................................................................................... 18

7.2 Temperature difference ................................................................................................................... 18

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7.3 Flow rate ................................................................................................................................................ 18

8 Heat transmission formula ............................................................................................................. 18

9 Metrological characteristics (Maximum Permissible Error, MPE) ................................... 19

9.1 General ................................................................................................................................................... 19

9.2 Values of maximum permissible errors ..................................................................................... 19

9.2.1 Maximum permissible relative errors of complete thermal energy meters................. 19

9.2.2 Maximum permissible relative error of sub-assemblies ..................................................... 20

9.3 Application of maximum permissible errors ........................................................................... 20

9.3.3 21

10 Environmental classification .......................................................................................................... 21

10.1 General ................................................................................................................................................... 21

10.2 Environmental class A (Domestic use, indoor installations) .............................................. 21

10.3 Environmental class B (Domestic use, outdoor installations) ........................................... 21

10.4 Environmental class C (Industrial installations) .................................................................... 21

10.5 Mechanical classes M1 to M3 .......................................................................................................... 21

11 Thermal energy meter specification ........................................................................................... 22

11.1 General ................................................................................................................................................... 22

11.2 Flow sensor ........................................................................................................................................... 22

11.3 Temperature sensor pair ................................................................................................................. 23

11.4 Calculator .............................................................................................................................................. 24

11.5 Complete meters ................................................................................................................................. 25

12 Information to be made available by the manufacturer or supplier ............................... 27

12.1 Installation instructions ................................................................................................................... 27

12.2 Parameter setting instructions...................................................................................................... 28

12.3 Adjustment instructions .................................................................................................................. 29

12.4 Maintenance instructions ................................................................................................................ 29

12.5 Information required when a heat meter is taken out of service for recycling and/or

disposal .................................................................................................................................................. 30

12.5.1 General ................................................................................................................................................... 30

12.5.2 Disassembly .......................................................................................................................................... 30

12.5.3 Recycling ................................................................................................................................................ 30

12.5.4 Disposal .................................................................................................................................................. 30

Annex A (normative) Heat coefficient formulae..................................................................................... 31

A.1 Water ....................................................................................................................................................... 31

A.2 Heat-conveying liquids other than water .................................................................................. 33

Annex B (normative) Flow conditioner package .................................................................................... 34

Annex C (normative) Fast response meters ............................................................................................. 36

Annex ZA (informative) Relationship between this European Standard and the essential

requirements of Directive 2014/32/EU aimed to be covered ........................................... 37

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European foreword

This document (prEN 1434-1) has been prepared by Technical Committee CEN/TC 176 “Thermal energy

meters”, the secretariat of which is held by SIS.
This document is currently submitted to the CEN Enquiry.
This document supersedes EN 1434-1:2015+A1:2018.
EN 1434, Thermal energy meters consists of the following parts:
— Part 1: General requirements
— Part 2: Constructional requirements
— Part 3: Data exchange and interfaces
— Part 4: Pattern approval tests
— Part 5: Initial verification tests
— Part 6: Installation, commissioning, operational monitoring and maintenance
In comparison to EN 1434-1:2015+A1:2018, the following changes have been made:

— the wording “flow straightener” has been changed to “flow conditioner” in the whole document;

— subclause 12.5 “Hints for disposal instructions” was replaced by the enlarged, new subclause 12.5

“Information required when a heat meter is taken out of service for recycling and/or”.

This document has been prepared under a mandate given to CEN by the European Commission and the

European Free Trade Association, and supports essential requirements of EU Directive(s).

For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this

document.
EN 1434-3 is maintained by CEN/TC 294.
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1 Scope

This document specifies the general requirements for thermal energy meters. Thermal energy meters are

instruments intended for measuring the energy which in a heat-exchange circuit is absorbed (cooling) or

given up (heating) by a liquid called the heat-conveying liquid. The thermal energy meter indicates the

quantity of thermal energy in legal units.
Electrical safety requirements are not covered by this document.
Pressure safety requirements are not covered by this document.
Surface mounted temperature sensors are not covered by this document.

This document covers meters for closed systems only, where the differential pressure over the thermal

load is limited.
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.

prEN 1434-2:2020, Thermal energy meters — Part 2: Constructional requirements
prEN 1434-4:2020, Thermal energy meters — Part 4: Pattern approval test

EN 60751, Industrial platinum resistance thermometers and platinum temperature sensors (IEC 60751)

EN 61010-1, Safety requirements for electrical equipment for measurement, control and laboratory use —

Part 1: General requirements (IEC 61010-1)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
3.1
response time
τ0,5

time interval between the instant when flow or temperature difference is subjected to a specified abrupt

change and the instant when the response reaches 50 % of the step value
3.2
fast response meter

meter suitable for heat exchanging circuits with rapid dynamic variations in the exchanged heat

Note 1 to entry: See also Annex C.
Under development
Under development
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3.3
rated voltage

voltage of the external power supply required to operate the thermal energy meter, conventionally the

voltage of the AC mains supply
3.4
rated operating conditions

conditions of use, giving the range of values of influence quantities, for which the metrological

characteristics of the instrument are within the specified maximum permissible errors

3.5
reference conditions

set of specified values of influence factors, fixed to ensure valid inter-comparison of results of

measurements
3.6
influence quantity

quantity, which is not the subject of the measurement, but which influences the value of the measurement

and or the indication of the measuring instrument
3.7
influence factors
influence quantity having a value within the rated operating conditions
3.8
disturbance
influence quantity having a value outside the rated operating conditions
3.9
types of errors
3.9.1
error (of indication)

indication of the measuring instrument minus the conventional true value of the measurand

3.9.2
intrinsic error
error of a measuring instrument determined under reference conditions
3.9.3
initial intrinsic error

error of a measuring instrument as determined once prior to performance tests and durability tests

3.9.4
durability error

difference between the intrinsic error after a period of use and the initial intrinsic error

3.9.5
maximum permissible error
MPE
highest values of the error (positive or negative) permitted
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3.10
Types of faults
3.10.1
fault

difference between the error of indication and the intrinsic error of the instrument

3.10.2
transitory fault

momentary variations in the indication, which cannot be interpreted, memorized or transmitted as

measurements
3.10.3
significant fault

fault greater than the absolute value of the MPE and not being a transitory fault

Note 1 to entry: If the MPE is ± 2 % then the significant fault is a fault larger than ± 2 %.

3.11
reference values of the measurand
RVM

specified value of the flow rate, the outlet temperature and the temperature difference, fixed to ensure

valid intercomparison of the results of measurements
3.12
conventional true value
quantity value attributed by agreement to a quantity for a given purpose

Note 1 to entry: A conventional true value is, in general, regarded as sufficiently close to the true value for the

difference to be insignificant for the given purpose.
EXAMPLE A true value is the heat coefficient according to Annex A.
3.13
meter model

different sizes of thermal energy meters or sub-assemblies having a family similarity in the principles of

operation, construction and materials
3.14
electronic device
device employing electronic elements and performing a specific function
3.15
electronic element

smallest physical entity in an electronic device which uses electron hole conduction in semi-conductors,

or electron conduction in gases or in a vacuum
3.16
qualifying immersion depth of a temperature sensor

immersion depth over which the sensor measures with an accurate temperature value

Note 1 to entry: The conditions to define the qualified immersion depth are written in prEN 1434-4:2020, 7.4.4.1.

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3.17
self-heating effect

increase in temperature signal that is obtained by subjecting each temperature sensor of a pair to a

continuous power dissipation of 5 mW when immersed to the qualifying immersion depth in a water

bath, having a mean water velocity of 0,1 m/s
3.18
thermal energy meter

instrument intended for measuring the energy which in a heat-exchange circuit is absorbed (cooling) or

given up (heating) by a liquid called the heat-conveying liquid
3.19
meters other than for heating
3.19.1
cooling meter

thermal energy meter designed for cooling applications at low temperatures, normally covering the

temperature range 2 °C to 30 °C and ΔΘ up to 20 K
3.19.2
bifunctional meters for change-over systems between heating and cooling
instrument measuring heating and cooling energy in two separate registers

Note 1 to entry: In other directives and requirements, bifunctional meters are called combined meters.

Key
No energy recording
Heating
Cooling
θ temperature of the inlet respectively outlet
Inlet
θ switching temperature for heating/cooling (e.g. 25 °C)
ΔΘ starting temperature difference of energy accumulation (e.g. 0,1 K)
ΔΘ minimum approved temperature difference (e.g. 3 K)
min
Figure 1 — Example for function of heating and cooling register
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3.20
flow direction
direction of the liquid going through the system from inlet to outlet

Note 1 to entry: The inlet is for the heating case the hot side and for the cooling case the cold side.

Note 2 to entry: In the literature the word “flow” is also being used for “inlet”, and the word “return” is also being

used for “outlet”.

Note 3 to entry: Different temperature values for θ for heating and cooling applications may also occur.

3.21
electrical pulse

electrical signal (voltage, current or change in resistance), that departs from an initial level for a limited

duration of time and ultimately returns to the original level
3.22
pulse output and input devices
3.22.1
pulse output device
functional part of flow sensor, calculator or auxiliary devices
EXAMPLE Remote displays or input devices of control systems.
3.22.2
pulse input device
functional part of flow sensor, calculator or auxiliary devices
EXAMPLE Pulse input for external water meter.
3.23
maximum admissible temperature

maximum temperature of the heat conveying liquid the meter can withstand in combination with the

maximum admissible working pressure and the permanent flow rate for short periods of time (< 1 h/day;

< 200 h/year) without a significant fault after the exposure to this maximum admissible temperature

3.24
durability

characteristic of a measuring instrument to keep the metrological characteristics over time (e.g. to fulfil

the double of MPE), provided that it is properly installed, maintained and used within the permissible

environmental conditions
3.25
long life flow sensor

flow sensor designed to have a longer lifetime than a normal flow sensor, which typically has a durability

of 5 years under the specified operating conditions
3.26
user interface

interface forming part of the instrument that enables information to be passed between a human user

and the measuring instrument or its components (e.g. display)
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3.27
communication interface

electronic, optical, radio or other technical interface that enables information via correct transceiving of

at least thermal energy to be passed between measuring instruments, sub-assemblies or external devices

3.28
meter for smart metering

thermal energy meter with the capability of data communication and support of smart metering

functionalities

Note 1 to entry: Data could be transmitted via user interface and/ or communication interface in fixed time

intervals and/or on request.

Note 2 to entry: For more information on smart meters, see standard series EN 13757 and

CEN/CLC/ETSI/TR 50572.
3.29
registration device

optional additional device fitted to the meter as an integral part or separate device, in order to register

the amount of thermal energy accumulated in additional registers during periods, depending on

conditions, e. g. flow rate, inlet or outlet temperatures, temperature differences or time points

3.30
register

component of a registration device which contains accumulated or actual values e. g. thermal energy,

volume, maximum flow rate, power or temperature
3.31
interval register

register which contains frequently accumulated or copied values used for registration of billing purposes

and/ or for controlling processes

Note 1 to entry: During consecutive time intervals values could be achieved by copying from an accumulating main

register which contains actual values of e.g. thermal energy or volume.

Note 2 to entry: During consecutive time intervals the measured process values of flow rate and/or temperature

could be additionally stored.
3.32
maximum flow
highest rate of flow which is expected at operating conditions
Note 1 to entry: For the limits of flow rates, see 5.3.
3.33

heat-conveying liquids other than water (mixed fluids, e.g. water glycol mixtures)

mixture of water with a defined proportion of another fluid e.g. mono-ethylene or propylene glycol

Note 1 to entry: Typical heat conveying liquids on the market consist of a base liquid (e.g. water with propylene

glycol) and additives to prevent corrosion or counteract chemical reactions like acid formation. The liquids often

differ in their constitution regarding their additives

Note 2 to entry: For many topics within this document the liquids can be classified in liquid categories according to

their base liquid (e.g. mono ethylene-based products, propylene glycol-based products, ethanol-based products)

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4 Types of instruments
4.1 General

For the purposes of this European Standard, thermal energy meters are defined either as complete

instruments or as combined instruments.
4.2 Complete instrument

A thermal energy meter, which does not have separable sub-assemblies as defined in 4.5.

4.3 Combined instrument
A thermal energy meter, which has separable sub-assemblies as defined in 4.5.
4.4 Hybrid instrument

A thermal energy meter, which for the purpose of pattern approval and verification can be treated as a

combined instrument as defined in 4.3 or combinations between sub-assemblies. However, after

verification, its sub-assemblies shall be treated as inseparable.
NOTE Hybrid instruments are often called “compact instruments”.
4.5 Sub-assemblies of a thermal energy meter, which is a combined instrument
4.5.1 General

The flow sensor, the temperature sensor pair and the calculator or a combination of these.

4.5.2 Flow sensor

A sub-assembly through which the heat-conveying liquid flows, at either the inlet or outlet of a heat-

exchange circuit, and which emits a signal, which is a function of the volume or the mass or the volumetric

or mass flow rate.
4.5.3 Temperature sensor pair

A sub-assembly (for mounting with or without pockets), which senses the temperatures of the heat-

conveying liquid at the inlet and outlet of a heat-exchange circuit.
4.5.4 Calculator

A sub-assembly, which receives signals from the flow sensor, and the temperature sensors and calculates

and indicates the quantity of thermal energy exchanged.
4.6 Equipment under test (EUT)
A sub-assembly, a combined sub-assembly or a complete meter subject to a test.
...

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