SIST EN 1434-1:2022

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.

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oSIST prEN 1434-1:2020

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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.

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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
)
1
— 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.


1)
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.
2
prEN 1434-2:2020, Thermal energy meters — Part 2: Constructional requirements
3
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.

2
Under development
3
Under development
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3.3
rated voltage
U
n
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)
hc
ΔΘ starting temperature difference of energy accumulation (e.g. 0,1 K)
hc
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.
hc
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.
...