Thermal energy meters - Part 2: Constructional requirements
This European Standard specifies 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 heat in legal units.
Electrical safety requirements are not covered by this European Standard.
Pressure safety requirements are not covered by this European Standard.
Surface mounted temperature sensors are not covered by this European Standard.
This standard covers meters for closed systems only, where the differential pressure over the thermal load is limited.
Thermische Energiemessgeräte - Teil 2: Anforderungen an die Konstruktion
Compteurs d'énergie thermique - Partie 2 : Prescriptions de fabrication
La présente Norme européenne spécifie les prescriptions de fabrication 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.
La présente Norme européenne ne traite pas des prescriptions de sécurité électrique.
La présente Norme européenne ne traite pas des prescriptions de sécurité relative à la pression.
La présente Norme européenne ne traite pas des sondes de température montées en surface.
La présente norme couvre les compteurs pour les systèmes fermés uniquement, où la pression
différentielle dans la charge thermique est limitée.
Merilniki toplote - 2. del: Konstrukcijske zahteve (vključno z dopolnilom A1)
Ta evropski standard določa konstrukcijske zahteve za merilnike toplote. Merilniki toplote so instrumenti, namenjeni merjenju energije, ki jo v krogotoku toplotne izmenjave absorbira (hlajenje) ali oddaja (ogrevanje) tekočina, imenovana tekočina za prenos toplote. Merilnik toplote podaja toploto v predpisanih enotah.
Ta evropski standard ne zajema električnih varnostnih zahtev.
Ta evropski standard ne zajema tlačnih varnostnih zahtev.
Ta evropski standard ne zajema površinsko nameščenih senzorjev temperature.
Ta standard zajema samo števce za zaprte sisteme, kjer je diferencialni tlak nad toplotno obremenitvijo omejen.
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Thermische Energiemessgeräte - Teil 2: Anforderungen an die KonstruktionCompteurs d'énergie thermique - Partie 2 : Prescriptions de fabricationThermal energy meters - Part 2: Constructional requirements17.200.10Toplota. KalorimetrijaHeat. CalorimetryICS:Ta slovenski standard je istoveten z:EN 1434-2:2015+A1:2018SIST EN 1434-2:2016+A1:2019en,fr,de01-marec-2019SIST EN 1434-2:2016+A1:2019SLOVENSKI
STANDARDSIST EN 1434-2:20161DGRPHãþD
SIST EN 1434-2:2016+A1:2019
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
t r s z ICS
s yä t r rä s r English Version
Thermal energy meters æ Part
tã Constructional requirements Compteurs d 5énergie thermique æ Partie
t ã Prescriptions de fabrication
Wärmezähler æ Teil
tã Anforderungen an die Konstruktion This European Standard was approved by CEN on
t r s w and includes Amendment
s approved by CEN on
s z July
t r s zä
egulations which stipulate the conditions for giving this European Standard the status of a national standard without any alterationä Upætoædate lists and bibliographical references concerning such national standards may be obtained on application to the CENæCENELEC Management Centre or to any CEN memberä
translation under the responsibility of a CEN member into its own language and notified to the CENæCENELEC Management Centre has the same status as the official versionsä
CEN members are the national standards bodies of Austriaá Belgiumá Bulgariaá Croatiaá Cyprusá Czech Republicá Denmarká Estoniaá Finlandá Former Yugoslav Republic of Macedoniaá Franceá Germanyá Greeceá Hungaryá Icelandá Irelandá Italyá Latviaá Lithuaniaá Luxembourgá Maltaá Netherlandsá Norwayá Polandá Portugalá Romaniaá Serbiaá Slovakiaá Sloveniaá Spainá Swedená Switzerlandá Turkey and United Kingdomä
EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre:
Rue de la Science 23,
t r s z CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Membersä Refä Noä EN
s v u væ tã t r s w ªA sã t r s z ESIST EN 1434-2:2016+A1:2019
EN 1434-2:2015+A1:2018 (E) 2 Contents Page European foreword . 3 1 Scope . 4 2 Normative references . 4 3 Terms and definitions . 5 4 Temperature sensors . 5 4.1 General . 5 4.2 Mechanical design . 5 4.3 Platinum temperature sensor . 10 4.4 Other temperature sensors . 12 5 Flow sensors . 13 5.1 Maximum admissible working pressure, PS in bar . 13 5.2 Sizes and dimensions . 13 5.3 Test signal output. 14 5.4 Adjusting device . 14 6 Calculators . 15 6.1 Terminals - specification and identification . 15 6.2 Batteries . 17 6.3 Dynamic behaviour . 17 6.4 Test signal output. 17 6.5 24 h interruption in supply voltage . 18 7 Complete meter . 18 8 Interfaces between sub-assemblies . 18 8.1 General . 18 8.2 Definitions for pulse device interfaces . 18 9 Marking and security seals . 21 9.1 Marking . 21 9.2 Sites for marking . 23 9.3 Security seals . 23 Annex A (informative) Examples of temperature sensors . 24 Annex B (normative) Input and output test signals . 35 Annex C (informative) Low voltage Power Supply for !thermal energy meters"and their sub-assemblies . 37 C.1 Remote supply . 37 C.2 Local external DC supply . 37 C.3 Power supply specifications . 38 Annex ZA (informative)
Relationship between this European Standard and the essential requirements of Directive2014/32/EU aimed to be covered . 39 Bibliography . 40
SIST EN 1434-2:2016+A1:2019
EN 1434-2:2015+A1:2018 (E) 3 European foreword This document (EN 1434-2:2015+A1:2018) 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 May 2019, and conflicting national standards shall be withdrawn at the latest by May 2019. 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 includes Amendment 1, approved by CEN on 2018-07-18. This document supersedes !EN 1434-2:2015". The start and finish of text introduced or altered by amendment is indicated in the text by tags !". 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 1434-2, !Thermal energy meters" consists of the following parts: — Part 1: General requirements — Part 2: Constructional requirements — Part 3: Data exchange and interfaces1) — Part 4: Pattern approval tests — Part 5: Initial verification tests — Part 6: Installation, commissioning, operational monitoring and maintenance In comparison to EN 1434-2:2007, the following changes have been made: — additional functionalities for smart metering applications are added; — minimum requirements for test signal output of calculators are added; — minimum requirements for test data interface of complete !thermal energy meters" are added; — new forms of pockets and sensors and parmeter setting and adjustment through interface are added. 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
1) EN 1434-3 is maintained by CEN/TC 294. SIST EN 1434-2:2016+A1:2019
EN 1434-2:2015+A1:2018 (E) 4 1 Scope This European Standard specifies 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 heat in legal units. Electrical safety requirements are not covered by this European Standard. Pressure safety requirements are not covered by this European Standard. Surface mounted temperature sensors are not covered by this European Standard. This standard covers meters for closed systems only, where the differential pressure over the thermal load is limited. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. 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, Flanges and their joints — Circular flanges for pipes, valves, fittings and accessories, PN designated — Part 1: Steel flanges EN 1092-2, Flanges and their joints — Circular flanges for pipes, valves, fittings and accessories, PN designated — Part 2: Cast iron flanges EN 1092-3, Flanges and their joints — Circular flanges for pipes, valves, fittings and accessories, PN designated — Part 3: Copper alloy flanges !EN 1434-1:2015+A1:2018, Thermal energy meters — Part 1: General requirements" EN 1434-3, Heat Meters — Part 3: Data exchange and interfaces EN 60751:2008, Industrial platinum resistance thermometers and platinum temperature sensors (IEC 60751:2008) EN 60947-5-6, 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) EN ISO 228-1, Pipe threads where pressure-tight joints are not made on the threads — Part 1: Dimensions, tolerances and designation (ISO 228-1) ISO 4903, Information technology — Data communication — 15-pole DTE/DCE interface connector and contact number assignments SIST EN 1434-2:2016+A1:2019
EN 1434-2:2015+A1:2018 (E) 5 3 Terms and definitions For the purposes of this document, the terms and definitions given in !EN 1434-1:2015+A1:2018" apply. 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 mm 0,5 up to 3 over 3 up to 6 over 6 up to 30 over 30 up to 120 over 120 up to 400 Tolerance mm ± 0,2 ± 0,3 ± 1 ± 1,5 ± 2,5 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. A suitable material has been shown to be EN 10088-3 — X6 Cr Ni Mo Ti 17 12 2. 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. SIST EN 1434-2:2016+A1:2019
EN 1434-2:2015+A1:2018 (E) 6 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. SIST EN 1434-2:2016+A1:2019
EN 1434-2:2015+A1:2018 (E) 7 Dimensions in millimetres
Key 1 temperature sensing element 4 outline of head probe 2 protective sheath 5 outline of permanently connected signal lead probe 3 sealing surface 6 inlet for signal cable – ø
¶ 9 mm G ½ B thread in accordance with EN ISO 228-1 A: < 30 mm or
¶ 50 mm for Pt1000 Alternative lengths B C (head probe only) 85 105 120 140 210 230 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. 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. SIST EN 1434-2:2016+A1:2019
EN 1434-2:2015+A1:2018 (E) 8 Dimensions in millimetres
Key A < 30 mm or
¶ 50 mm for Pt 1000
Alternative lengths B (head probe only) 105 140 230
1 temperature sensing element 3 outline of permanently connected signal lead probe 2 outline of head probe 4 inlet for signal cable – ø
¶ 9 mm Corresponding to c11 in EN ISO 286-2, rounded to 2 decimals Figure 3 — Temperature probes - Type PL (head or cable) SIST EN 1434-2:2016+A1:2019
EN 1434-2:2015+A1:2018 (E) 9 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 rounded to 2 decimals G ½ B thread in accordance with EN ISO 228-1 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.7). SIST EN 1434-2:2016+A1:2019
EN 1434-2:2015+A1:2018 (E) 10 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.11 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.11 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.11 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 R2 internal wire resistance 2 protective sheath R3 signal lead resistance 3 mounting thread
4 signal leads Figure 5 — Temperature probe with permanently connected signal leads SIST EN 1434-2:2016+A1:2019
EN 1434-2:2015+A1:2018 (E) 11
Key R1 temperature sensing element resistance 1 temperature sensing element R2 internal wire and terminals resistance 2 protective sheath
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) as follows: ()2t01ABRRtt=++=(1)=where=Rt is the resistance value at temperature t in - see Figures 5 and 6); R0 is the resistance value at temperature 0
A is 3,908 3 × 10-3 °C-1; B is -5,775 × 10-7 °C-2. 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 precisely 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. SIST EN 1434-2:2016+A1:2019
EN 1434-2:2015+A1:2018 (E) 12 To ensure best performance and measurement stability the 4-wire method and Pt 100 or Pt 500-platinium resistance temperature sensors should be used. 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. Table 2 — Maximum lengths of leads for Pt 100 temperature sensors Lead cross section mm2 Max. length for Pt 100 m 0,22 2,5 0,50 5,0 0,75 7,5 1,50 15,0 For sensors of higher resistances the limiting value can be extended proportionally. 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
Àä 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. A cross-section of 0,5 mm2 is recommended for head sensors and a minimum cross-section of 0,14 mm2 for cable sensors. 4.3.6 Thermal response time The manufacturer shall declare the temperature sensor response time 0,5 as defined in EN 60751:2008, 6.5.2 using the test method in EN 60751:2008, 188.8.131.52. 4.4 Other temperature sensors Other types of temperature sensors are permissible, but shall be tested as part of the calculator. SIST EN 1434-2:2016+A1:2019
EN 1434-2:2015+A1:2018 (E) 13 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 sensor is designated either by the thread size of the end connections or by the nominal diameter of the flange. For each flow sensor size there is a corresponding value of the permanent flow rate qp and a set of lengths as given in Tables 3 and 4. The values in Table 3 apply to the connecting screw and/or the flange and the overall lengths. For sizes larger than DN 250 the flow sensor dimensions are not standardised. Table 3 — Preferred dimensions qp m3/h Overall length mm Threaded end connection Flanged connection DN Overall length mm Threaded end connection Flanged connection DN Overall length mm Threaded end connections 0,6 110 G ¾ B 15 190 G 1 B 20
1,0 130 G ¾ B 15 190 G 1 B 20 110 G ¾ B 1,5 165 G ¾ B 15 190 G 1 B 20 110 G ¾ B 2,5 190 G 1 B 20
130 G 1 B 3,5 260 G 1 ¼ B 25
150 G 1 ¼ B 6,0 260 G 1 ½ B 32 260 G 1 ¼ B 25 150 G 1 ¼ B 10 300 G 2 B 40
200 G 2 B 15 300
To achieve the necessary overall length adaptor pieces can be fitted. The adjacent lengths larger or smaller than the preferred lengths may be adopted for qp
· 10 m3/h. Tolerances on the overall length shall be: — up to 300 mm 02−=mm;=—=from=350=to=600=mm=03−=mm.=Threaded=connection=SIST EN 1434-2:2016+A1:2019
EN 1434-2:2015+A1:2018 (E) 14 Dimensions for the threaded end connections are specified in Table 4. Threads shall comply with EN ISO 228-1. Figure 7 outlines the dimensions a and b. Flanged connection Flanged end connections shall comply with EN 1092-1, EN 1092-2 and EN 1092-3 (as appropriate) for a nominal pressure corresponding to that of the flow sensor. Table 4 — Threaded end connections
Range of size and minimum thread lengths in mm
Figure 7 — Outline of the dimensions a and b in Table 4 5.3 Test signal output For test purposes, it is required that either high resolution pulses using an adaptor according to Annex B shall be provided, or data from a data interface, as described in EN 1434-3, using an adapter (if necessary) shall be employed. The discrimination of these test outputs shall be such, that in a test at qi (defined in !EN 1434-1:2015+A1:2018, 5.3.3"), the measurement error resulting from the number of pulses is not greater than 0,8 %, and the test period of 1 h for sizes qp < 10 m3/h or 1,5 h for qp
· 10 m3/h, is not exceeded. The nominal relationship between the signal emitted and the quantity measured shall be declared by the manufacturer. Output names used at pulse output connections are given in Annex B. For flow sensors having data test interface only (without high resolution pulse outputs), at least the following data shall be available: Unique meter ID and volume register. 5.4 Adjusting device The flow sensor may be fitted with an adjustment device making it possible to correct the relationship between the indicated and the true value. Thread a b G ¾ B 10 12 G 1 B 12 14 G 1 ¼ B 12 16 G 1 ½ B 13 18 G 2 B 13 20 SIST EN 1434-2:2016+A1:2019
EN 1434-2:2015+A1:2018 (E) 15 For flow sensors the adjustment shall be available through a data interface, if the flow sensors are intended for re-adjustment. This is not applicable for flow sensors with mechanical adjustment. In any case the adjusting shall be protected by security sealing. 6 Calculators 6.1 Terminals - specification and identification 6.1.1 General The numbers specified in Table 5 or Table 6 respectively shall be used for the inscriptions on the terminals provided. Terminals not required can be omitted. The screening of a screened cable may be connected to the terminal board for earthing purposes. The screening of a screened cable may be anchored to the terminal board to prevent damage of the cable by pulling, provided the cable used is suitable for this. 6.1.2 Terminals for signal leads The terminals shall meet the following requirements: a) maximum cable cross-section 1,5 mm2; b) distance between terminals 5 mm; c) suitable for stranded wire; d) the contact resistance for a two-wire Pt 100 transition between the terminal and the wire shall be
¶ 5 m. The change in contact resistance with time shall be < 5 m; e) to ensure best performance and measurement stability the 4-wire method should be used. SIST EN 1434-2:2016+A1:2019
EN 1434-2:2015+A1:2018 (E) 16 Table 5 — Numbering of terminals Terminal no. Signal descriptor Signal identification 1 High temperature sensor/assigned to No. 5a
2 High temperature sensor/assigned to No. 6a
3 Low temperature sensor/assigned to No. 7a
4 Low temperature sensor/assigned to No. 8a
5 High temperature sensor
6 High temperature sensor
7 Low temperature sensor
8 Low temperature sensor
9 Flow sensor, positive supply voltage output
10 Flow sensor signal input
11 Flow sensor reference input
12 Test signals reference output -U 13 High resolution energy test signal output CH 14 Flow pulse test signal input CI 15 High resolution volume test signal input CT 16 Remote counting pulses energy output CE 17 Remote counting pulses energy output, reference level
18 Remote counting pulses volume output CV 19 Remote counting pulses volume output, reference level
20 CL 0 - interface with 4-wire RX+/RTX+ 21 CL 0 - interface with 4-wire RX-/RTX- 22 CL 0 - interface with 4-wire TX+ 23 CL 0 - interface with 4-wire TX- 24 Meter bus interface
25 Meter bus interface
a Used only with 4-wire method. Rules about numbering of terminals: a) there may be more than one terminal, each of them having the same number, if they are electrically connected (e.g. connection of temperature sensor cable's shield); b) terminals and their numbers can be omitted, if corresponding signals are not present; c) for signals other than those described, terminal number 50 and upwards shall be used. SIST EN 1434-2:2016+A1:2019
EN 1434-2:2015+A1:2018 (E) 17 6.1.3 Terminals for connection to the mains supply Two or, preferably, three terminals shall be provided, which shall be suitable for stranded wire up to a cross-section of 2,5 mm2. Cables with permanently fitted connections may also be used. Table 6 — Numbering and marking of the mains terminals Terminal No Marking 26 Earth symbol 27 N 28 L If no polarity indication is needed, the "N" and "L" can be replaced by the standardized symbol for a mains connection. 6.2 Batteries The life time of the batteries shall be declared by the manufacturer. 6.3 Dynamic behaviour The manufacturer shall declare how the temperature measurements and integration are related to the flow sensor signal and time. 6.4 Test signal output A high resolution energy signal is required for testing purposes. The resolution shall be sufficiently high so that at a test at the lower limit of temperature difference and/or flow rate, the additional error caused by the resolution of the energy signal can be shown to be insignificant. The nominal relationship between the high resolution signal and the energy reading shall be stated by the manufacturer. The energy signal as specified above shall be available either directly at the calculator connection terminal or at the terminal of a testing adapter as stated in Annex B. The test signal shall be either pulses with a defined value of pulses/energy increment or a data output, specially defined, or a display with correspondingly high resolution. Pulse output names used at output connections are given in Annex B. For calculators having data test interface only (without high resolution pulse outputs), at least the following data shall be available: — unique meter ID, — energy register, — volume register, — inlet temperature, and — outlet