SIST EN 1434-2:2007
(Main)Heat meters - Part 2: Constructional requirements
Heat meters - Part 2: Constructional requirements
This European Standard specifies the constructural requirements and applies to heat meters, that is to instruments intended for measur¬ing the heat which, in a heat-exchange circuit, is absorbed or given up by a liquid called the heat-conveying liquid. The heat 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.
Wärmezähler - Teil 2: Anforderungen an die Konstruktion
Diese Europäische Norm gilt für Wärmezähler, d. h. für Geräte, die dazu dienen, die Wärmemenge zu
messen, die in einem Wärmetauscherkreislauf durch eine als Wärmeträgerflüssigkeit bezeichnete Flüssigkeit
aufgenommen oder abgegeben wird. Der Wärmezähler zeigt die Wärmemenge in gesetzlichen Einheiten an.
Elektrische Sicherheitsanforderungen werden in dieser Norm nicht behandelt.
Den Druck betreffende Sicherheitsanforderungen werden in dieser Norm nicht behandelt.
Oberflächenmontierte Sensoren werden in dieser Norm nicht behandelt.
Teil 1 beschreibt allgemeine Anforderungen.
Compteurs d'énergie thermique - Partie 2: Prescriptions de fabrication
La présente Norme européenne spécifie les prescriptions de fabrication et s'applique aux compteurs d'énergie thermique, c'est-à-dire aux instruments destinés à mesurer l'énergie thermique qui, dans un circuit d'échange thermique, est absorbée (refroidissement) ou cédée (échauffement) 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 exigences de sécurité électrique.
La présente Norme européenne ne traite pas des exigences de sécurité relative à la pression.
La présente Norme européenne ne traite pas des sondes de température montées en surface.
Toplotni števci - 2. del: Konstrukcijske zahteve
General Information
Relations
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Heat meters - Part 2: Constructional requirementsToplotni števci - 2. del: Konstrukcijske zahteveCompteurs d'énergie thermique - Partie 2: Prescriptions de fabricationWärmezähler - Teil 2: Anforderungen an die KonstruktionTa slovenski standard je istoveten z:EN 1434-2:2007SIST EN 1434-2:2007en17.200.10Toplota. KalorimetrijaHeat. CalorimetryICS:SIST EN 1434-2:1997/A1:2002SIST EN 1434-2:19971DGRPHãþDSLOVENSKI
STANDARDSIST EN 1434-2:200701-maj-2007
EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 1434-2February 2007ICS 17.200.10Supersedes EN 1434-2:1997
English VersionHeat meters - Part 2: Constructional requirementsCompteurs d'énergie thermique - Partie 2: Prescriptions defabricationWärmezähler - Teil 2: Anforderungen an die KonstruktionThis European Standard was approved by CEN on 7 January 2007.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN 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 translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2007 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 1434-2:2007: E
EN 1434-2:2007 (E) 2 Contents Page Foreword.4 1 Scope.5 2 Normative references.5 3 Temperature sensors.5 3.1 General.5 3.2 Mechanical design.6 3.2.1 General.6 3.2.2 Materials of temperature probe sheath and pocket.6 3.2.3 Dimensions of direct mounted short probes - Type DS.6 3.2.4 Dimensions of direct mounted long probes - Type DL.6 3.2.5 Dimensions of pocket mounted long probes - Type PL.9 3.2.6 Dimensions of temperature pocket.9 3.2.7 Design of short probes with respect to installation.11 3.2.8 Design of long probes with respect to installation.11 3.3 Platinum temperature sensor.12 3.3.1 Specialised definitions for 2 wire temperature probes.12 3.3.2 Resistance characteristics.13 3.3.3 Signal leads.14 3.3.4 Temperature sensors for the 2-wire method.14 3.3.5 Temperature sensors for the 4-wire method.14 3.3.6 Thermal response time.15 3.4 Other temperature sensors.15 4 Flow sensors.15 4.1 Maximum admissible working pressure, PS in bar.15 4.2 Sizes and dimensions.15 4.3 Test signal output.17 4.4 Adjusting device.17 5 Calculators.17 5.1 Mechanical dimensions for calculators for domestic use.17 5.2 Terminals - specification and identification.18 5.2.1 General.18 5.2.2 Terminals for signal leads.18 5.2.3 Terminals for connection to the mains supply.19 5.3 Batteries.20 5.4 Dynamic behaviour.20 5.5 Test signal output.20 5.6 24 h interruption in supply voltage.20 6 Complete meter.20 7 Interfaces between sub-assemblies.20 7.1 Definitions for pulse device interfaces.21 7.1.1 General.21 7.1.2 Electrical connection.21 7.1.3 Classification of pulse output devices.21 7.1.4 Timing and electrical parameters for pulse output devices (other than test signals).22 7.1.5 Classification of pulse input devices.22 7.1.6 Timing and electrical parameter for pulse input devices.23 7.1.7 Compatibility.23 8 Marking and security seals.24
EN 1434-2:2007 (E) 3 8.1 Marking.24 8.1.1 General.24 8.1.2 Temperature sensor pairs.24 8.1.3 Pockets.24 8.1.4 Flow sensor.24 8.1.5 Calculator.25 8.1.6 Complete meter.25 8.2 Sites for marking.26 8.3 Security seals.26 Annex A (informative)
Examples of temperature sensors.27 Annex B (normative)
Input and output test signals.36 Annex C (informative)
Low voltage Power Supply for heat meters and their sub-assemblies.39 C.1 Remote supply.39 C.1.1 Voltage (DC or AC).39 C.1.2 Current available.39 C.1.3 Cabling requirements.39 C.2 Local external DC supply.39 C.2.1 Voltage.39 C.2.2 Other data.40 C.3 Power supply specifications.40 Annex ZA (informative)
Relationship between this European Standard and the Essential Requirements of
EU Directive 2004/22/EC, MID.41 Bibliography.42
EN 1434-2:2007 (E) 4 Foreword This document (EN 1434-2:2007) has been prepared by Technical Committee CEN/TC 176 “Heat meters”, the secretariat of which is held by DS. 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 August 2007, and conflicting national standards shall be withdrawn at the latest by August 2007. This document supersedes EN 1434-2:1997. The other parts are Part 1 - General 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 According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EN 1434-2:2007 (E) 5 1 Scope This European Standard specifies the constructional requirements and applies to heat meters, that is to instruments intended for measuring the heat which, in a heat-exchange circuit, is absorbed (cooling) or given up (heating) by a liquid called the heat-conveying liquid. The heat 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. 2 Normative references The following referenced documents are indispensable for the application 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 1434-1:2007, Heat meters — Part 1: General requirements prEN 1434-3, Heat meters — Part 3: Data exchange and interfaces EN 60751:1995, Industrial platinum resistance thermometer sensors (IEC 60751:1983 + A1:1986) 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- 6:1999) EN ISO 228-1, Pipe threads where pressure tight joints are not made on the threads — Part 1: Dimensions, tolerances and designation (ISO 228-1:2000) ISO 4903, Information technology — Data communication — 15-pole DTE/DCE interface connector and contact number assignments ISO 7005-1, Metallic flanges — Part 1: Steel flanges ISO 7005-2, Metallic flanges — Part 2: Cast iron flanges ISO 7005-3, Metallic flanges — Part 3: Copper alloy and composite flanges 3 Temperature sensors 3.1 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 supplier. Where no dimensional tolerance is specified, the values shall be taken from Table 1.
EN 1434-2:2007 (E) 6 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
3.2 Mechanical design 3.2.1 General For pipe sizes up to and including DN 250, 3 different temperature sensor types are standardised: 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. 3.2.2 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 3.2.3 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 supplier. 3.2.4 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 supplier.
EN 1434-2:2007 (E) 7 Dimensions in millimetres
Key 1 temperature sensing element 2 protective sheath 3 sealing ring Figure 1 — Temperature probes type DS
EN 1434-2:2007 (E) 8 Dimensions in millimetres
Key G 1/2 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
1 temperature sensing element 2 protective sheath 3 sealing face 4 outline of head probe 5 outline of permanently connected signal lead probe 6 inlet for signal cable – ø ≤ 9 mm Figure 2 — Temperature probes type DL (head or cable)
EN 1434-2:2007 (E) 9 3.2.5 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 supplier. 3.2.6 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.6 a) and b) 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.
EN 1434-2:2007 (E) 10 Dimensions in millimetres
Key 1)
Corresponding to c11 in ISO 286-2, rounded to 2 decimals A: < 30 mm or ≤ 50 mm for PT1000 Alternative lengths B (head probe only) 105 140 230
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 Figure 3 — temperature probes – Type PL (head or cable)
EN 1434-2:2007 (E) 11 Dimensions in millimetres
Key 1)
Corresponding to H11 in ISO 286-2 rounded to 2 decimals G 1/2 B thread in accordance with EN ISO 228-1 Alternative lengths C D 85 ≤ 100 120 ≤ 135 210 ≤ 225
1 sealing face 2 probe clamping screw with provision for security sealing Figure 4 — Temperature pocket
3.2.7 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). 3.2.8 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.
EN 1434-2:2007 (E) 12 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.8 B), using welded-in boss (see Annex A, Figure A.6 b)). b)
in a pipe –DN 50 mounted at an angle 45º to the direction of the flow with the tip pointing into the flow (see Annex A, Figure A.8 C), using a welded in boss (see Annex A,
Figure A.6 b)). c)
in a pipe DN 65 to DN 250, mounted perpendicular to the flow (see Annex A, Figure A.8 D), using a welded-in boss (see Annex A, Figure A.6 a)). 3.3 Platinum temperature sensor 3.3.1 Specialised 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
EN 1434-2:2007 (E) 13
Figure 6 — Head sensor temperature probe Key R1
temperature sensing element resistance 1
temperature sensing element R2
internal wire and terminals resistance 2
protective sheath
3
mounting thread
4
outline of head
3.3.2 Resistance characteristics The calibration of temperature sensors shall be traceable to national temperature standards. The intermediate values of the heat meter temperature sensor shall be interpolated using the EN 60751 equation as follows: R1 = R0 (1 + At + Bt2) where R1 is the resistance value at temperature t in Ω (excluding cable resistance - see Figures 5 and 6); R0 is the resistance value at temperature 0 ºC in Ω (base value) (excluding cable resistance); A is 3,908 3 × 10-3 ºC-1;
EN 1434-2:2007 (E) 14 B is - 5,775 × 10-7 ºC-2. NOTE It is assumed that the national temperature standards are established with reference to ITS-90 - The International Temperature Scale of 1990. 3.3.3 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. 3.3.4 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
0,50
0,75
1,50
2,5
5,0
7,5
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 flow and return 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 flow and return 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. 3.3.5 Temperature sensors for the 4-wire method If the cable length requirements in 3.3.4 cannot be fulfilled, the 4-wire method shall be used. The connections shall be clearly identifiable so that they cannot be confused.
EN 1434-2:2007 (E) 15 A cross-section of 0,5 mm2 is recommended for head sensors and a minimum cross-section of 0,14 mm2 for cable sensors. 3.3.6 Thermal response time The supplier shall declare the temperature sensor response time τ0,5 as defined in 4.3.3 of EN 60751:1995, using the test method in 4.3.3.3 of EN 60751:1995. 3.4 Other temperature sensors Other types of temperature sensors are permissible, but shall be tested as part of the calculator. 4 Flow sensors 4.1 Maximum admissible working pressure, PS in bar The maximum admissible working pressure shall be declared by the manufacturer. 4.2 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.
EN 1434-2:2007 (E) 16
Table 3 — Dimensions
Preferred
Also acceptable
Also
acceptable qp m3/h Overall length
mm Threaded end con-nections Flanged connec-tions
DN Overall length
mm Threaded end con-nections Flanged connec-tions
DN Overall length
mm Threaded end con-nections
0,6 1,0 1,5 2,5 3,5 6,0 10 15 25 40 60 100 150 250 400
110 130 165 190 260 260 300 300 300 350 350 350 500 500 600
G 3/4 B G 3/4 B G 3/4 B G
1
B G 1 1/4 B G 1 1/2 B
G 2 B
15 15 15 20 25 32 40 50 65 80 100 125 150 200 250
190 190 190
260
270
300 360
G 1 B G 1 B G 1 B
G 1 1/4 B
20 20 20
25
50
80 100
110 110 130
G 3/4 B G 3/4 B G 1 B
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 š≥ 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 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 ISO 7005-1, 7005-2 and 7005-3 (as appropriate) for a nominal pressure corresponding to that of the flow sensor.
EN 1434-2:2007 (E) 17
Table 4 — Threaded end connections Range of size and minimum thread lengths in mm
Thread
a
b
G 3/4 B
G 1 B
G 1 1/4 B
G 1 1/2 B
G 2 B
10
12
12
13
13
12 14 16 18 20
Figure 7 — Outline of the dimensions a and b in Table 4 4.3 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 serial interface, as described in prEN 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 5.3 of
EN 1434-1:2007), 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 supplier. Output names used at pulse output connections are given in Annex B. 4.4 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. 5 Calculators 5.1 Mechanical dimensions for calculators for domestic use The casing of calculators intended for wall mounting shall have maximum dimensions given in Figure 8.
EN 1434-2:2007 (E) 18 If the casing is large enough, the centre distances for the mounting holes shall be as in Figure 8. If the casing is smaller, an adapter plate shall be available. Dimensions in millimetres
Figure 8 — Maximum dimensions 5.2 Terminals - specification and identification 5.2.1 General The numbers specified 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. 5.2.2 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 mΩ. The change in contact resistance with time shall be < 5 mΩ.
EN 1434-2:2007 (E) 19 Table 5 — Numbering of terminals Terminal no. Signal descriptor Signal iden-tification
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
High temperature sensor/assigned to No. 5*
High temperature sensor/assigned to No. 6 * Low temperature
sensor/assigned to No. 7 * Low temperature
sensor/assigned to No. 8 * High temperature sensor High temperature sensor Low temperature sensor Low temperature sensor Flow sensor, positive supply voltage output Flow sensor signal input Flow sensor reference input Test signals reference output High resolution energy test signal output Flow pulse test signal input High resolution volume test signal input Remote counting pulses energy output Remote counting pulses energy output, reference level Remote counting pulses volume output Remote counting pulses volume output, reference level CL 0 - interface with 4-wire CL 0 - interface with 4-wire CL 0 - interface with 4-wire CL 0 - interface with 4-wire Meter bus interface Meter bus interface
-U CH CI CT CE
CV
RX+/RTX+ RX-/RTX- TX+ TX-
* 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. 5.2.3 Terminals for connection to the mains s
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