1、BRITISH STANDARD BS 5754:1987 Incorporating Amendment No. 1 Specification for Electrical analogue and state signals for use in coal mines UDC 622.489:621.398:621.3.037.3BS5754:1987 This British Standard, having been prepared under the directionof the Mining and Quarrying Requisites Standards Committ
2、ee, was published underthe authority of the Board ofBSI and comes into effect on 27February1987 BSI 10-1999 First published February1980 First revision February1987 The following BSI references relate to the work on this standard: Committee reference MQE/25 Draft for comment 84/78553 DC ISBN 0 580 1
3、5789 X Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Mining and Quarrying Requisites Standards Committee (MQE/-) to Technical Committee MQE/25, upon which the following bodies were represented: Association of British Mining Equipment C
4、ompanies British Coal Council for Electrical Equipment for Flammable Atmospheres (BEAMA) Health and Safety Executive Amendments issued since publication Amd. No. Date of issue Comments 6481 November 1990 Indicated by a sideline in the marginBS5754:1987 BSI 10-1999 i Contents Page Committees responsi
5、ble Inside front cover Foreword ii Section 1. General 1 Scope 1 2 Definitions 1 3 Design 1 4 Power supplies 1 5 Interconnection via multicore cables 1 6 Connection to non-intrinsically safe apparatus 2 7 Marking 2 8 Documentation 2 Section 2. D.C. voltage analogue signals (type V) 9 Signal output ci
6、rcuit 3 10 Signal measuring circuit 3 Section 3. State signals (type S) 11 Signal output circuit 4 12 Signal detection circuit 4 Appendix A Examples of safety couplers used where signals are routed through multicore cables 5 Figure 1 Arrangement of detection diodes 4 Publications referred to Inside
7、back coverBS5754:1987 ii BSI 10-1999 Foreword This revision of BS5754 has been prepared under the direction of the Mining and Quarrying Requisites Standards Committee. It supersedes BS5754:1980 which is withdrawn. In this revision the opportunity has been taken to review the text in the light of exp
8、erience. Terms such as “data transmission outstation” which in1980 described the usual destination for analogue signals has been replaced by “signal measuring circuit” which is a better description of current and future practice. The rapid growth of control and monitoring of activities below ground
9、in coal mines has stimulated the development of many new types of apparatus giving intrinsically safe outputs in the form of electrical analogue or state signals. These outputs may be used for local indication/control or connected into other intrinsically safe apparatus. The design of the interconne
10、cted apparatus calls for a range of expertise that can only be supplied by a number of different manufacturers, each of whose apparatus has to be able to work effectively as part of a complete system for a mine. The purpose of this specification is to promote compatibility between interconnected app
11、aratus of different manufacture. 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. Compliance with a British Standard does not of itself confer immunity from legal obligations. Attentio
12、n is drawn to the Health and Safety at Work etc. Act1974, the Factories Act1961, the Mines and Quarries Act1954, the Regulations made under these Acts, and also any other appropriate statutory requirements or byelaws. These place responsibility for complying with certain specific safety requirements
13、 on the manufacturer and the user. The address of the recognized certification authority in the UK for Group I (coal mining) apparatus for intrinsic safety purposes is as follows: Health and Safety Executive HSE (M) Certification Support Unit Harpur Hill Buxton Derbyshire SK17 9JN Summary of pages T
14、his document comprises a front cover, an inside front cover, pages i and ii, pages1 to 6, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS575
15、4:1987 BSI 10-1999 1 Section 1. General 1 Scope This British Standard specifies requirements for apparatus incorporating signal circuits intended to be certified intrinsically safe for use in coal mines and which have inputs or outputs, as appropriate, in the form of d.c. voltage analogue signals (t
16、ype V), or state signals (type S). It specifies those electrical input and output characteristics of signal sources and signal loads necessary to achieve operational compatibility and also to simplify design for compliance with the relevant standards for intrinsic safety. Section 1 specifies the gen
17、eral requirements applicable to both types of signals. Sections 2 and 3 contain specific requirements for voltage analogue and state signals respectively. NOTEThe titles of the publications referred to in this standard are listed on the inside back cover. 2 Definitions For the purposes of this Briti
18、sh Standard the following definitions apply. 2.1 powered device an apparatus that requires an internal or external power source for the signal measuring circuit, e.g.a tape recorder is a powered signal measuring instrument 2.2 operational fault a defect of any component or connection which affects t
19、he performance of the device NOTEThis should not be confused with faults affecting only the intrinsic safety of the device; these are defined in BS5501-7. 2.3 galvanic connection a continuous conducting d.c. path 2.4 safety coupler a safety device that is used to limit the transfer of electrical ene
20、rgy between intrinsically safe circuits 2.5 safety barrier a safety device that is used to limit the transfer of electrical energy from a non-intrinsically safe to an intrinsically safe circuit 3 Design The signal input or output circuits shall comply with either: a) BS 5501-7 for Group I category “
21、ia” apparatus; or b) BS 1259, Class 1. 4 Power supplies 4.1 All apparatus requiring an external power supply shall be capable of working from either a power supply specified in BS6182, or a non-intrinsically safe mains power supply having a voltage within the limits of+10% and25% of the nominal valu
22、e. In the latter case, apparatus for use in a hazardous area shall be either housed in a flameproof enclosure, or afforded an alternative type of protection as specified in BS5501. NOTEThe value of the mains voltage is not specified as a requirement of this standard. The preferred values are120V and
23、/or240V, or550V and/or1100V r.m.s.50Hz frequency. 4.2 Reversal of power supply polarity shall not damage the apparatus. 5 Interconnection via multicore cables 1) Analogue and state signals shall only be routed through multicore cables containing other circuits complying with this standard provided t
24、hat either: a) it is permitted by the certification documents; or b) connection is made by way of a safety coupler unit acceptable to a certifying authority for this usage. NOTEExamples of safety couplers that have been used for this purpose are shown inAppendix A. 1) When the outputs from several s
25、ignal circuits complying with this standard are to be carried in the same multicore cable, the intrinsic safety of the arrangement will need to be assessed under cable fault conditions on the basis that two or more power sources, each having a maximum open-circuit voltage of22.4Vd.c., i.e.the maximu
26、m output voltage of a type18DC power supply complying with BS6182, as specified in9.3 and10.3, may be interconnected. The purpose of the safety coupler is to limit the maximum open-circuit voltage of the source, thereby permitting more than one source to be interconnected in any manner without degra
27、dation of intrinsic safety. The requirements for the full assessment of faults in multicore cables are given in BS5501-9.BS5754:1987 2 BSI 10-1999 6 Connection to non-intrinsically safe apparatus Analogue signal sources shall only be connected to non-intrinsically safe apparatus provided that either
28、: a) it is permitted by the certification documents; or b) connection is made by way of a safety barrier unit acceptable to a certifying authority for this usage and which is sited in a safe area, or is contained within a flameproof enclosure, or is afforded an alternative type of protection as spec
29、ified in BS5501. 7 Marking Apparatus shall be marked with the number and date of this British Standard, i.e.BS 5754:1987 2) , followed by the type of signal, i.e.“type V”, or “typeS” as appropriate. NOTEThis is additional to any marking required by a certifying authority. 8 Documentation The manufac
30、turer/supplier of apparatus complying with this standard shall produce and make available such information as is necessary for the safe and correct use of the apparatus. 2) Marking BS5754:1987 on or in relation to a product is a claim by the manufacturer that the product has been manufactured to the
31、 requirements of the standard. The accuracy of such a claim is therefore solely the manufacturers responsibility. Enquiries as to the availability of third party certification should be addressed to the appropriate certification body.BS5754:1987 BSI 10-1999 3 Section 2. D.C. voltage analogue signals
32、 (type V) 9 Signal output circuit 9.1 The analogue signal shall be+0.4V at the zero or lowest point of the measured range and+2.0V at the highest point of the range. In addition, the common of the signal output circuit shall be referenced to0V of the power supply. NOTEA signal offset of0.4V provides
33、 a means of distinguishing some operational faults (e.g.power supply failure) from a true zero indication. 9.2 The apparatus shall be designed such that operational faults shall cause the analogue output to fall to less than0.2V or to rise to greater than2.2V. NOTE 1Whilst it may not be possible to
34、design the apparatus so that every type of fault will cause the output to fall below0.2V, or to rise above2.2V, the designer should aim to meet the requirement in the case of the majority of types of faults and, in particular, the types of faults most likely to occur. NOTE 2It is preferred that faul
35、ts should cause the analogue output to fall to less than0.2V, rather than rise to greater than2.2V. 9.3 The open circuit voltage at the signal output terminals or between any signal output terminal and earth shall not exceed22.4V with any two faults (as defined in BS5501-7). 9.4 The effective source
36、 resistance of the signal output circuit shall not exceed507 when connected to a load resistance of10007. 9.5 The signal output circuit shall have no galvanic connection to earth within the apparatus. 9.6 The manufacturer shall state the accuracy and output characteristic of the signal as a percenta
37、ge of full scale, and the test conditions used. NOTEThe following test conditions are preferred: a) connection to a load resistance of10007; b) a power supply as specified in4.1; c) an ambient temperature range of5 C to+40 C; d) a humidity up to95% r.h. normally not condensing. Any condensation whic
38、h may form when the apparatus is first installed underground should not permanently affect its accuracy. 10 Signal measuring circuit 10.1 The resistance presented to the signal at its point of measurement shall be not less than10007. 10.2 Powered devices shall be designed so that with any two faults
39、 (as defined in BS5501-7) the maximum open circuit voltage that can appear at the signal input terminals or between any terminal and earth does not exceed22.4V. 10.3 Each unearthed input lead of a powered device receiving the signal shall incorporate a resistance of not less than10007. Each resistor
40、 shall be infallible and be rated in accordance with BS5501-7 for a maximum input voltage of22.4V.BS5754:1987 4 BSI 10-1999 Section 3. State signals (type S) 11 Signal output circuit 11.1 The state signal shall be either a fluctuating on-off (flashing) signal, or a continuous simple on or off signal
41、. 11.2 The signal output circuit shall be separated from other circuits within the same apparatus by an infallible distance in accordance with BS5501-7. The circuit shall have no galvanic connection to earth within the apparatus. 11.3 Where relay contacts are used, each shall have a minimum current
42、rating of100mAd.c. and a minimum voltage rating of22.4Vd.c. The contact resistance shall not exceed250 m7 at the rated current. 11.4 Where solid-state devices are used, the voltage drop in the closed condition shall not exceed1.0V at20mA and the current in the open condition shall not exceed2004A at
43、22.4V. 11.5 A fluctuating state signal shall be an alternately open and closed circuit derived from relay contacts or solid-state devices. The normal state shall be indicated by a closed condition for100 20ms at15 3s intervals. An alarm or warning condition shall be indicated by a closed condition f
44、or100 20ms at500 50ms intervals. Where an intermediate early warning alarm is required, it shall be indicated by a closed condition for100 20ms at2000 200ms intervals. All changes between open and closed circuit conditions shall take place in less than5ms. NOTEAs far as is reasonably practicable an
45、operational fault condition should be indicated by a continuous open or a continuous closed condition. 11.6 To provide operational fault detection on external circuits each continuous on or off state signal circuit shall include, in series with one outgoing connection, a diode (or provision for fitt
46、ing a diode) having a peak inverse rating of200V and a forward current rating of1A. Where changeover contacts are used there shall be provision for connecting diodes as shown inFigure 1. NOTEThe double-diode arrangement provides a means of distinguishing between two operational states. 12 Signal det
47、ection circuit 12.1 The maximum output current of the detection circuit shall not exceed100mA. 12.2 The detection circuit shall incorporate a resistor of not less than1007 connected in each unearthed lead. Each resistor shall be infallible and shall be rated in accordance with BS5501-7 assuming the
48、voltage to be22.4V. 12.3 The detection circuit shall be designed so that with any two faults (as defined in BS5501-7) the maximum open circuit voltage that can appear at the signal terminals or between any terminal and earth shall not exceed22.4V. Figure 1 Arrangement of detection diodesBS5754:1987
49、BSI 10-1999 5 Appendix A Examples of safety couplers used where signals are routed through multicore cables6 blankBS5754:1987 BSI 10-1999 Publications referred to BS 1259, Intrinsically safe electrical apparatus and circuits for use in explosive atmospheres. BS 5501, Electrical apparatus for potentially explosive atmospheres. BS 5501-7, Intrinsic safety “i”. BS 5501-9, Intrinsically safe electrical systems “i”. BS 6182, Intrinsically safe power supplies for use in coal mines. BS 6182-1, Specification for d.c. power supplies. BS 6182-2, Specification for a.c. po
