1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS 7951:2000 ICS 17.220.2
2、0 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Specification for Electricity meters Alternating-current single-phase static watt-hour telemeters of accuracy class 1 or 2This British Standard, having been prepared under the direction of the Electrotechnical Sector Committee,
3、 was published under the authority of the Standards Committee and comes into effect on 15 May 2000 BSI 05-2000 The following BSI references relate to the work on this standard: Committee reference PEL/13 Draft for comment 96/210564 DC ISBN 0 580 33159 8 BS 7951:2000 Amendments issued since publicati
4、on Amd. No. Date Comments Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Committee PEL/13, Electricity meters, upon which the following bodies were represented: BCEMA BEAMA Metering Association (BMA) Electricity Association Electr
5、icity Pool of England and Wales Energy Systems Trade Association Flag Association Institution of Electrical Engineers Office of Electricity Regulation (OFFER) Co-opted membersBS 7951:2000 BSI 05-2000 i Contents Page Committees responsible Inside front cover Foreword ii Introduction 1 1 Scope 1 2 Nor
6、mative references 1 3 Terms and definitions 1 4 Requirements 1 4.1 Rated electrical values 1 4.2 Mechanical requirements 2 4.3 Ambient conditions 3 4.4 Electrical requirements 3 4.5 Electromagnetic compatibility (EMC) 4 4.6 Accuracy 4 4.7 Radio teleswitch module 4 4.8 Other requirements 5 5 Tests 5
7、5.1 General 5 5.2 Interaction affecting accuracy 5 5.3 Interaction causing emission of spurious pulses 5ii BSI 05-2000 BS 7951:2000 Foreword This British Standard has been prepared by Technical Committee PEL/13. As far as possible, the clause numbering of this standard has been structured to corresp
8、ond with that of BS EN 61036:1997. SI units in accordance with the relevant parts of BS 5775:1993 are used throughout this standard. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Co
9、mpliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 5 and a back cover. The BSI copyright notice displayed in this document indicates when the document wa
10、s last issued. BSI 05-2000 1 BS 7951:2000 Introduction BS 7647 describes a radio-controlled switch (radio teleswitch) which is used with an electricity meter to provide facilities for implementing a multiple-rate tariff. Technological development now allows the functions of a radio teleswitch to be
11、integrated within a static electricity meter as specified in BS EN 61036. This obviates the need for two separate devices. Such an integrated device is known as a (radio) telemeter. A telemeter may incorporate output switches and local communications facilities via an optical port, and is intended f
12、or use in those locations in domestic, industrial or commercial premises where it is custom and practice to install electricity meters, and tariff and load control devices. The telemeter has energy registers associated with each metrological element for the registration of controlled and/or uncontro
13、lled energy usage. Timing for effect of such registers is provided by an internal clock, synchronized from time signals decoded by the radio teleswitch module. 1 Scope This British Standard specifies requirements for alternating-current single-phase static watt-hour telemeters of accuracy class 1 or
14、 class 2, with one or two measuring elements. It applies to telemeters of protective class I or class II. NOTE Accuracy classes and protective classes are as applied in BS EN 61036:1997. 2 Normative references The following normative documents contain provisions which, through reference in this text
15、, constitute provisions of this British Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. For undated references, the latest edition of the publication referred to applies. BS 7647:1993, Specification for radio teleswitches for tariff
16、and load control. BS 7856:1996, Code of practice for design of alternating current, watt-hour meters for active energy (classes 1 and 2). BS EN 55022:1995, Limits and methods of measurement of radio disturbance characteristics of information technology equipment. BS EN 60068-2-6:1996, Environmental
17、testing Test methods Test Fc Vibration (sinusoidal). BS EN 60068-2-27:1993, Environmental testing Test methods Environmental testing procedures Tests Test Ea and guidance Shock. BS EN 60529:1992, Degrees of protection provided by enclosures (IP code). BS EN 61036:1997, Alternating current static wat
18、t-hour meters for active energy (classes 1 and 2). BS EN 61107:1996, Data exchange for meter reading, tariff and load control Direct local data exchange. 3 Terms and definitions For the purposes of this British Standard, the following terms and definitions apply, together with relevant definitions g
19、iven in BS 7647:1993 and BS EN 61036:1997. 3.1 telemeter electricity meter incorporating a radio teleswitch module for tariff and load control 3.2 radio teleswitch module part of the telemeter which receives and decodes the radio teleswitch signals and transmits appropriate information to its output
20、 circuits 3.3 local communication port infra-red input/output communications facility as specified in BS EN 61107:1996 3.4 output switch switch controlled by information from the radio teleswitch module NOTE Output switches include physical switches, with outputs accessible externally, and internal
21、logic switches, which set parameters such as tariff rate within the telemeter. 3.5 load switch physical output switch for controlling space-heating and/or water-heating equipment 3.6 auxiliary switch physical output switch for signalling changes of rate to external equipment 4 Requirements 4.1 Rated
22、 electrical values 4.1.1 Rated voltage (U n ) The telemeter shall be rated for a nominal supply voltage of 230 V. 4.1.2 Rated current Measuring elements shall be rated at 20 A basic (I b ) and 100 A maximum (I max ). NOTE The total current which a two-element telemeter passes will not in practice ex
23、ceed 120 A, irrespective of the sum of the I max rating of each measuring element. This is because the meter will be controlled by a suppliers fuse rated at up to 100 A, which will operate to break the circuit at about this level, depending on the fusing factor. 4.1.3 Standard frequency The telemete
24、r shall be suitable for a standard supply frequency of 50 Hz.2 BSI 05-2000 BS 7951:2000 4.2 Mechanical requirements 4.2.1 General The telemeter shall conform to BS EN 61036:1997, 4.2.1. 4.2.2 Case The telemeter shall conform to BS EN 61036:1997, 4.2.2. 4.2.3 Window If the cover is not transparent, o
25、ne or more windows shall be provided for reading the display(s) and observation of the operation indicator(s), if fitted; see 4.2.11. The window(s) shall be made of a transparent material, which cannot be removed undamaged without breaking a seal. 4.2.4 Terminals and terminal block(s) Terminal block
26、(s) shall conform to BS EN 61036:1997, 4.2.4. If the telemeter does not have double insulation, it shall have a protective earth terminal as specified in BS EN 61036:1997, 4.2.4. The dimensions of the telemeter and the spacing of fixing holes and terminals shall conform to BS 7856:1996, Table 1 and
27、Figure 1. Terminals related to the primary measuring element(s), offering unrestricted supply, shall conform to BS 7856:1996, Figures 2 and 3 in respect of the arrangement of line and neutral. NOTE A telemeter may have terminals additional to those shown in BS 7856:1996. 4.2.5 Terminal covers Termin
28、al covers shall conform to BS EN 61036:1997, 4.2.5. 4.2.6 Clearance and creepage distances Clearance and creepage distances as described in BS EN 61036:1997, 4.2.6, shall conform to the values specified for indoor meters for a voltage phase-to-earth of 300 V in BS EN 61036:1997, Table 3a or Table 3b
29、 as appropriate. 4.2.7 Supplementary insulation for insulating encased telemeters of protective class II Insulating encased telemeters of protective class II (see BS EN 61036:1997, 3.4.6) shall conform to BS EN 61036:1997, 4.2.7. 4.2.8 Resistance to heat and fire The telemeter shall conform to BS EN
30、 61036:1997, 4.2.8. 4.2.9 Protection against penetration by dust and water When tested in accordance with BS EN 61036:1997, 5.2.5, the telemeter shall conform to the degree of protection IP51 as specified in BS EN 60529:1992, but without suction in the meter. 4.2.10 Resistance to impact, shock and v
31、ibration 4.2.10.1 After testing in accordance with BS 7647:1993, 10.2.1, the case and terminal cover of the telemeter shall sustain no damage which could affect the function of the telemeter, and it shall not be possible to touch any live part. NOTE Slight damage which does not impair the protection
32、 against indirect contact or the penetration of solid objects, dust and water, is acceptable. 4.2.10.2 After testing in accordance with BS EN 60068-2-27:1993 under the conditions given in BS 7647:1993, 10.2.2, the telemeter shall show no damage and shall operate correctly, and the position of the sw
33、itches shall be unchanged. 4.2.10.3 After testing in accordance with BS EN 60068-2-6:1996 under the conditions given in BS 7647:1993, 10.2.3, the telemeter shall show no damage and shall operate correctly, and the position of the switches shall be unchanged; components and wiring shall remain fasten
34、ed and secure. 4.2.11 Display Display of the values measured by the telemeter shall conform to BS EN 61036:1997, 4.2.11. The display of a two-element telemeter shall indicate the consumption of both elements. NOTE The consumption of the two elements need not be indicated simultaneously. 4.2.12 Outpu
35、t device(s) The telemeter shall have at least one test output device accessible from the front and capable of being monitored by suitable testing equipment. Operation indicator(s), if fitted, shall be visible from the front and shall indicate operation of each measuring element. If a local communica
36、tions port is fitted, it shall conform to BS EN 61107:1996. 4.2.13 Output switches 4.2.13.1 General Up to two load switches shall be associated with each measuring element. 4.2.13.2 Indication of switch states The state of each load switch shall be indicated. 4.2.13.3 Number of operations Switches s
37、hall conform to BS 7647:1993, 5.8.3, with respect to the number of operations. 4.2.13.4 Non-automatic operation of output switches For test purposes only, there shall be a safe means of setting each output switch to the on or off condition. 4.2.13.5 Acoustic noise levels Acoustic noise levels of the
38、 output switches shall conform to BS 7647:1993, 5.8.5. BSI 05-2000 3 BS 7951:2000 1) Marking BS 7951:2000 on or in relation to a product represents a manufacturers declaration of conformity, i.e. a claim by or on behalf of the manufacturer that the product meets the requirements of the standard. The
39、 accuracy of the claim is solely the claimants responsibility. Such a declaration is not to be confused with third-party certification of conformity. 4.2.14 Marking 4.2.14.1 Nameplate The nameplate of the telemeter shall conform to BS EN 61036:1997, 4.2.13.1, with the addition of the following: 1) t
40、he designation “Telemeter to BS 7951:2000” 1) ; 2) the rated breaking currents of the output switches to which external access is possible; 3) the aerial position, A or B as indicated in BS 7647:1993, Figure 2, where a fixed aerial is fitted. If appropriate, the marking of the number of phases and t
41、he number of wires item c) of BS EN 61036:1997, 4.2.13.1 shall be presented in a manner which indicates that the telemeter has two elements. The marking shall be indelible, distinct and readable from outside the telemeter. 4.2.14.2 Connection diagrams and terminal marking The telemeter shall be inde
42、libly marked with a diagram of connections. If the terminals of the telemeter carry a marking, the corresponding marking shall appear on the diagram. 4.3 Ambient conditions The telemeter shall conform to BS EN 61036:1997, 4.3 for an indoor meter. When tested in accordance with BS EN 61036:1997, 5.3.
43、1 to 5.3.3, the telemeter shall show no damage or change of information and shall operate correctly. 4.4 Electrical requirements NOTE The requirements given in 4.4.2 to 4.4.6 apply to each measuring element of the telemeter 4.4.1 Power consumption The total power consumption of the telemeter, includ
44、ing all measuring elements, electronic circuits and output switches, shall not exceed the values given in Table 1. Table 1 Power consumption Number of elements Power consumption W VA One 3 10 Two 4 15 The power consumption in each voltage circuit and in each current circuit shall conform to BS EN 61
45、036:1997, 4.4.1, when tested in accordance with BS EN 61036:1997, 5.4.1. 4.4.2 Output switches 4.4.2.1 Rated voltage Output switches shall be designed for a rated voltage of 230 V. 4.4.2.2 Rated current Each switch shall be able to break under the values of current given in Table 2. Table 2 Switch b
46、reaking current Values in amperes Load condition Switch breaking current Switch rating 22 58 0 100 Linear ohmic load cos u = 1: current 22 58 01 0 0 Inductive load cos u = 0.4: current 11 01 01 0 4.4.3 Effect of supply variations 4.4.3.1 Voltage range A telemeter, including its output switches, shal
47、l have a specified operating range for supply voltage from 0.9U n to 1.1U n , where U n is the rated supply voltage (see 4.1). The limit range of operation shall be from 0 to 1.15U n . NOTE The terms “specified operating range” and “limit range of operation” are defined in BS EN 61036:1997. 4.4.3.2
48、Voltage dips and short interruptions When the telemeter is tested in accordance with BS EN 61036:1997, 5.4.2, there shall be no change of more than 0.01 kWh in any of its registers, and the test output shall not produce a signal equivalent of more than 0.01 kWh. NOTE For requirements relating specif
49、ically to the radio teleswitch module, see 4.7.6. 4.4.3.3 Effect of short-time over-currents After a short-time over-current of 200 A has been passed for 500 s through any terminal of the telemeter designed to supply power at 230 V, no flashover, disruptive charge or puncture shall occur when the telemeter is tested in accordance with BS EN 61036:1997, 5.4.6.3. A short-time over-current of up to 3 kA for one half-cycle at rated frequency shall not cause a variation of error greater than 0.3 A in any measuring circuit, with a power factor of unity. The
