SIST EN 1434-2:2022

SLOVENSKI STANDARD
SIST EN 1434-2:2022
01-november-2022
Nadomešča:
SIST EN 1434-2:2016+A1:2019
Merilniki toplote - 2. del: Konstrukcijske zahteve
Thermal energy meters - Part 2: Constructional requirements
Thermische Energiemessgeräte - Teil 2: Anforderungen an die Konstruktion
Compteurs d'énergie thermique - Partie 2 : Prescriptions de fabrication
Ta slovenski standard je istoveten z: EN 1434-2:2022
ICS:
17.200.20 Instrumenti za merjenje Temperature-measuring
temperature instruments
SIST EN 1434-2:2022 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 1434-2:2022

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SIST EN 1434-2:2022


EN 1434-2
EUROPEAN STANDARD

NORME EUROPÉENNE

September 2022
EUROPÄISCHE NORM
ICS 17.200.20 Supersedes EN 1434-2:2015+A1:2018
English Version

Thermal energy meters - Part 2: Constructional
requirements
Compteurs d'énergie thermique - Partie 2 : Thermische Energiemessgeräte - Teil 2:
Prescriptions de fabrication Anforderungen an die Konstruktion
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 1434-2:2022 E
worldwide for CEN national Members.

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SIST EN 1434-2:2022
EN 1434-2:2022 (E)
Contents Page
European foreword . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 Temperature sensors . 7
4.1 General. 7
4.2 Mechanical design . 7
4.2.1 General. 7
4.2.2 Materials of temperature probe sheath and pocket . 7
4.2.3 Dimensions of direct mounted short probes - Type DS . 8
4.2.4 Dimensions of direct mounted long probes - Type DL . 8
4.2.5 Dimensions of pocket mounted long probes - Type PL . 9
4.2.6 Dimensions of temperature pocket. 10
4.2.7 Design of short probes with respect to installation . 11
4.2.8 Design of long probes with respect to installation . 12
4.3 Platinum temperature sensor . 12
4.3.1 Specialized definitions for 2 wire temperature probes . 12
4.3.2 Resistance characteristics . 13
4.3.3 Signal leads . 13
4.3.4 Temperature sensors for the 2-wire method . 14
4.3.5 Temperature sensors for the 4-wire method . 14
4.3.6 Thermal response time . 14
4.3.7 Qualifying immersion depth of a temperature sensor . 14
4.4 Other temperature sensors . 14
5 Flow sensors . 15
5.1 Maximum admissible working pressure, PS in bar . 15
5.2 Sizes and dimensions . 15
5.3 Test signal output . 16
5.4 Adjusting device . 17
6 Calculators . 17
6.1 Terminals - specification and identification . 17
6.1.1 General. 17
6.1.2 Terminals for signal leads . 17
6.1.3 Terminals for connection to the mains supply . 19
6.2 Batteries . 19
6.3 Dynamic behaviour . 19
6.4 Test signal output . 19
6.5 24 h interruption in supply voltage . 20
7 Complete meter . 20
8 Interfaces between sub-assemblies . 21
8.1 General. 21
8.2 Definitions for pulse device interfaces . 21
8.2.1 General. 21
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EN 1434-2:2022 (E)
8.2.2 Electrical connection . 21
8.2.3 Classification of pulse output devices . 21
8.2.4 Timing and electrical parameters for pulse output devices (other than test signals) . 22
8.2.5 Classification of pulse input devices . 22
8.2.6 Timing and electrical parameter for pulse input devices . 23
8.2.7 Compatibility . 23
9 Marking and security seals . 24
9.1 Marking . 24
9.1.1 General . 24
9.1.2 Temperature sensor pairs . 24
9.1.3 Pockets . 24
9.1.4 Flow sensor . 24
9.1.5 Calculator . 25
9.1.6 Complete meter . 25
9.2 Sites for marking . 26
9.3 Security seals . 26
Annex A (informative) Examples of temperature sensors . 27
Annex B (normative) Input and output test signals . 39
Annex C (informative) Low voltage power supply for the thermal energy meters and their
subassemblies . 42
C.1 Remote supply . 42
C.1.1 Voltage (DC or AC) . 42
C.1.2 Current available . 42
C.1.3 Cabling requirements . 42
C.2 Local external DC supply . 42
C.2.1 Voltage . 42
C.2.2 Other data . 42
C.3 Power supply specifications . 43
Annex ZA (informative) Relationship between this European Standard and the essential
requirements of Directive2014/32/EU aimed to be covered . 44
Bibliography . 45

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SIST EN 1434-2:2022
EN 1434-2:2022 (E)
European foreword
This document (EN 1434-2:2022) 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 1434-2:2015+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 with EN 1434-2:2015+A1:2018, the following changes have been made:
— Figure A.10 “Threaded pipe fitting G1/2B, G3/4B, G1B, G1 1/4B and G1 1/2B sizes” has been
updated;
— in 4.2.2 “Materials of temperature probe sheath and pocket” another suitable material has been
added.
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

1
EN 1434-3 is maintained by CEN/TC 294.
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SIST EN 1434-2:2022
EN 1434-2:2022 (E)
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
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SIST EN 1434-2:2022
EN 1434-2:2022 (E)
1 Scope
This document is applicable to the constructional 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 1092-1:2018, Flanges and their joints — Circular flanges for pipes, valves, fittings and accessories, PN
designated — Part 1: Steel flanges
EN 1092-2:1997, Flanges and their joints — Circular flanges for pipes, valves, fittings and accessories, PN
designated — Part 2: Cast iron flanges
EN 1092-3:2003, Flanges and their joints — Circular flanges for pipes, valves, fittings and accessories, PN
designated — Part 3: Copper alloy flanges
EN 1434-1:2022, Thermal energy meters — Part 1: General requirements
EN 1434-3:2015, Heat meters — Part 3: Data exchange and interfaces
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 60947-5-6:2000, Low-voltage switchgear and controlgear — Part 5-6: Control circuit devices and
switching elements — DC interface for proximity sensors and switching amplifiers (NAMUR) (IEC 60947-5-
6:1999)
EN ISO 228-1:2003, Pipe threads where pressure-tight joints are not made on the threads — Part 1:
Dimensions, tolerances and designation (ISO 228-1:2000)
ISO 4903:1989, Information technology — Data communication — 15-pole DTE/DCE interface connector
and contact number assignments
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EN 1434-2:2022 (E)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 1434-1:2022 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
4 Temperature sensors
4.1 General
The temperature sensor sub-assembly shall consist of platinum resistance temperature sensors
selected as matched pairs.
Other types of temperature sensor pairs may be used, where the sub-assembly consists, inseparably, of
temperature sensors and calculator.
The maximum admissible working pressure shall be declared by the manufacturer.
Where no dimensional tolerance is specified, the values shall be taken from Table 1.
Table 1 — Tolerances
Dimension
over 6 up to over 30 up to over 120 up to
0,5 up to 3 over 3 up to 6
30 120 400
mm
Tolerance
±0,2 ±0,3 ±1 ±1,5 ±2,5
mm
4.2 Mechanical design
4.2.1 General
For pipe sizes up to and including DN 250, 3 different temperature sensor types are standardized:
— direct mounted short probes - Type DS;
— direct mounted long probes - Type DL;
— pocket mounted long probes - Type PL.
Types PL and DL can be either head probes or have permanently connected signal leads. Type DS shall
have permanently connected signal leads only.
4.2.2 Materials of temperature probe sheath and pocket
The temperature pocket and the protective sheath of direct mounted probes shall be of a material that
is adequately strong and resistant to corrosion and has the requisite thermal conductivity.
Examples of suitable materials are:
EN 10088-3:2014-12 – X2 Cr Ni Mo 17 13 2 (also known as W.nr. 1.4404)
or
EN 10088-3:2014-12 – X6 Cr Ni Mo Ti 17 12 2 (also known as W.nr. 1.4571)
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EN 1434-2:2022 (E)
4.2.3 Dimensions of direct mounted short probes - Type DS
The dimensions shall be as given in Figure 1.
Further non-normative information is given in Annex A, Figure A.1. The qualifying immersion depth
shall be 20 mm – or less if so specified by the manufacturer.
Dimensions in millimetres

Key
1 temperature sensing element
2 protective sheath
3 sealing ring
4 ejection device
A < 15 mm
B 27,5 mm or 38 mm or 60 mm
Figure 1 — Temperature probes type DS
4.2.4 Dimensions of direct mounted long probes - Type DL
The dimensions shall be as given in Figure 2.
Further information is given in Annex A, Figures A.2 and A.3.
The qualifying immersion depth shall be 50 % of the length B – or less if so specified by the
manufacturer.
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EN 1434-2:2022 (E)
Dimensions in millimetres

Key
1 temperature sensing element
2 protective sheath
3 sealing surface
4 outline of head probe
5 outline of permanently connected signal lead probe
6 inlet for signal cable – ø ≤ 9 mm
G1/2B thread in accordance with EN ISO 228-1:2003
A < 30 mm or ≤ 50 mm for Pt 1000
B 85 mm or 120 mm or 210 mm
Figure 2 — Temperature probes type DL (head or cable)
4.2.5 Dimensions of pocket mounted long probes - Type PL
The dimensions shall be as given in Figure 3.
Further information is given in Annex A, Figures A.4 and A.5.
The qualifying immersion depth shall be 50 % of the length B for the shortest pocket specified – or less
if so specified by the manufacturer.
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EN 1434-2:2022 (E)
Dimensions in millimetres

Key
1 temperature sensing element
2 outline of head probe
3 outline of permanently connected signal lead probe
4 inlet for signal cable – ø ≤ 9 mm
a
Corresponding to c11 in EN ISO 286-2, rounded to 2 decimals
A < 30 mm or ≤ 50 mm for Pt 1000
B 105 mm or 140 mm or 230 mm (head probe only)
Figure 3 — Temperature probes - Type PL (head or cable)
4.2.6 Dimensions of temperature pocket
The temperature pocket is designed for use with type PL temperature probes only. It is designed to be
capable of being inserted through a pipe wall to which has been externally brazed or welded a boss (see
Annex A, Figure A.9) and in this respect only, it is interchangeable with a direct mounted long probe of
corresponding insertion length. The dimensions shall be as given in Figure 4.
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EN 1434-2:2022 (E)
Dimensions in millimetres

Key
1 sealing face
2 probe clamping screw with provision for security sealing
a
Corresponding to H11 in EN ISO 286-2:2010 rounded to 2 decimals
G1/2B thread in accordance with EN ISO 228-1:2003

Alternative lengths
C D
85 ≤ 100
120 ≤ 135
210 ≤ 225
Figure 4 — Temperature pocket
4.2.7 Design of short probes with respect to installation
The sensor shall be mounted perpendicular to the flow and with the sensing element inserted to at least
the centre of the pipe.
For internal pressures up to 16 bar, the sensor shall be designed to fit in a pipe fitting (see Annex A,
Figure A.10).
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4.2.8 Design of long probes with respect to installation
The sensor shall be mounted with the sensing element inserted to at least the centre of the pipe.
The sensor shall be designed to fit in the following types of installation, (for internal pressures up to
PN 16):
a) in a pipe DN 50 mounted with the tip pointing into the flow in a bend (see Annex A, Figure A.12 b),
using welded-in boss (see Annex A, Figure A.9);
b) in a pipe DN 50 mounted at an angle 45° to the direction of the flow with the tip pointing into the
flow (see Annex A, Figure A.12 c), using a welded-in boss (see Annex A, Figure A.9);
c) in a pipe DN 65 to DN 250, mounted perpendicular to the flow (see Annex A, Figure A.12 d), using a
welded-in boss (see Annex A, Figure A.9).
4.3 Platinum temperature sensor
4.3.1 Specialized definitions for 2 wire temperature probes

Key
R1 temperature sensing element resistance 1 temperature sensing element
R internal wire resistance 2 protective sheath
2
R signal lead resistance 3 mounting thread
3
  4 signal leads
Figure 5 — Temperature probe with permanently connected signal leads
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Key
R temperature sensing element resistance 1 temperature sensing element
1
R internal wire and terminals resistance 2 protective sheath
2
  3 mounting thread
  4 signal leads
Figure 6 — Head sensor temperature probe
4.3.2 Resistance characteristics
The calibration of temperature sensors shall be traceable to national temperature standards. The
intermediate values of the thermal energy meter temperature sensor shall be interpolated using
Formula (1) defined in EN 60751:2008, 4.1 as follows:
2
R R 1++At Bt (1)
( )
t 0
where
R is the resistance value at temperature t in Ω (excluding cable resistance - see Figures 5 and
t
6);
R is the resistance value at temperature 0 °C in Ω (base value) (excluding cable resistance);
0
−3 −1
A is 3,908 3 × 10 °C ;
−7 −2
B is −5,775 × 10 °C .
NOTE It is assumed that the national temperature standards are established with reference to ITS-90 - The
International Temperature Scale of 1990.
4.3.3 Signal leads
For signal leads, leads with strands can be used, or in the case of head probes, solid wires. The lead ends
shall be definitely trimmed, if strands are used (e.g. by lead end sleeves). Solder-coating of the lead ends
to prevent splicing is not permissible.
A soldered joint to connect the temperature probe signal lead to the calculator is only permitted in the
case of non-interchangeable temperature probes.
For screened cables for temperature sensors there shall be no connection between the screen and the
protecting sheet.
To ensure best performance and measurement stability the 4-wire method and Pt 100 or Pt 500-
platinium resistance temperature sensors should be used.
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4.3.4 Temperature sensors for the 2-wire method
The length and cross sectional area of signal leads of paired resistance sensors of separable sub-
assemblies shall be equal.
The length of the signal lead as supplied by the manufacturer shall not be changed.
The length shall be within the values given in Table 2. For sensors of higher resistances the limiting
value can be extended proportionally.
Table 2 — Maximum lengths of leads for Pt 100 temperature sensors
Lead cross section Max. length for Pt 100
2
mm m
0,22 2,5
0,50 5,0
0,75 7,5
1,50 15,0
NOTE The values given in Table 2 have been obtained in the following manner:
It is assumed, that the difference in temperature of the leads does not exceed one third of the
temperature difference between inlet and outlet pipes.
The maximum permissible length of lead for each lead cross section was then calculated, having decided
that the error created may not be allowed to exceed 0,2 times the maximum permissible error of the
temperature probe pair and using the knowledge of the different resistances created by the
temperature differences between the inlet and outlet leads.
The influence of the length of a signal lead can be neglected, if the total resistance of a lead for a Pt 100
temperature sensor does not exceed two times 0,2 Ω.
4.3.5 Temperature sensors for the 4-wire method
If the cable length requirements in 4.3.4 cannot be fulfilled, the 4-wire method shall be used.
The connections shall be clearly identifiable so that they cannot be confused.
2 2
A cross-section of 0,5 mm is recommended for head sensors and a minimum cross-section of 0,14 mm
for cable sensors.
4.3.6 Thermal response time
The manufacturer shall declare the temperature sensor response time τ as defined in EN 60751:2008,
0,5
3.11 using the test method in EN 60751:2008, 6.5.2.
4.3.7 Qualifying immersion depth of a temperature sensor
The manufacturer shall declare the qualifying immersion depth as defined in EN 1434-4:2022, 7.4.4.1.
4.4 Other temperature sensors
Other types of temperature sensors are permissible, but shall be tested as part of the calculator.
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EN 1434-2:2022 (E)
5 Flow sensors
5.1 Maximum admissible working pressure, PS in bar
The maximum admissible working pressure shall be declared by the manufacturer.
5.2 Sizes and dimensions
The flow se
...