1、BRITISH STANDARD BS6353:1983 Specification for Underground loudspeaker communication systems in coal mines UDC 654.939.1:621.395.623.7/.8:622.23BS6353:1983 This BritishStandard, having been prepared under the directionof the Mining and Quarrying Requisites Standards Committee, was published underthe
2、 authority of the BoardofBSI and comes intoeffecton 29April1983 BSI 12-1999 The following BSI references relate to the work on this standard: Committee reference MQE/25 Draft for comment81/75758 DC ISBN 0 580 11939 4 Committees responsible for this BritishStandard This BritishStandard was published
3、under the direction of the Mining and Quarrying Requisites Standards Committee MQE/-. Its preparation was entrusted to Technical Committee MQE/25 upon which the following bodies were represented: Association of British Mining Equipment Companies Council for Electrical Equipment for Flammable Atmosph
4、eres (BEAMA) Health and Safety Executive National Association of Colliery Overmen, Deputies and Shotfirers (NACODS) National Coal Board National Union of Mineworkers Amendments issued since publication Amd. No. Date of issue CommentsBS6353:1983 BSI 12-1999 i Contents Page Committees responsible Insi
5、de front cover Foreword ii 1 Scope 1 2 Definitions 1 3 Electrical interface characteristics 1 4 Interconnection facilities 1 5 Tone signals 1 6 Transmission distance 1 7 Marking 2 8 Documentation 2 Appendix A Design of safety couplers and barriers 4 Appendix B Cable 4 Figure 1 Underground loudspeake
6、r communication system 3 Figure 2 System electrical parameters 3 Figure 3 Safety coupler 4 Figure 4 Safety barrier 5 Table 1 Electrical interface characteristics 2 Publications referred to Inside back coverBS6353:1983 ii BSI 12-1999 Foreword This BritishStandard has been prepared under the direction
7、 of the Mining and Quarrying Requisites Standards Committee. Underground loudspeaker communication systems provide local speech communication and broadcast alarm signals for the safe and efficient operation ofassociated machinery. The systems are generally fitted with facilities for communication wi
8、th the surface and/or for interconnection with other underground communication systems. It is envisaged that it will be necessary to interconnect systems made by different manufacturers and if problems arising from such interconnection are to be avoided, systems have to be compatible. The purpose of
9、 this standard is therefore to promote compatibility between loudspeaker communications systems 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 wi
10、th a British Standard does not of itself confer immunity from legal obligations. Attention is drawn to the Health and Safety at Work etc. Act1974, the Mines and Quarries Act1954, the Regulations made under these Acts, and also any other appropriate statutory requirements or byelaws. These place resp
11、onsibility for complying with certain specific safety requirements on the manufacturer and the user. The address of the recognized certification authority in the United Kingdom for Group1 (coal mining) apparatus for intrinsic safety purposes is as follows: Health and Safety Executive HSE (M) Certifi
12、cation Support Unit Harpur Hill Buxton Derbyshire SK179JN. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, pages1 to6, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. Thi
13、s will be indicated in the amendment table on the inside front cover.BS6353:1983 BSI 12-1999 1 1 Scope This BritishStandard specifies requirements for underground loudspeaker communication systems that are equipped with the facility for connecting speech and other audio signals to another loudspeake
14、r communication system and/or to an appropriate surface switchboard to form a loudspeaker communication network. Electrical input and output characteristics of underground loudspeaker communication systems necessary to achieve operational compatibility when they are interconnected are specified. The
15、 requirements for tone signals specified in clause5 do not apply to signals that are not transmitted to another system. This standard is applicable to underground loudspeaker communication systems that are intended to be certified intrinsically safe for use in coal mines in accordance with BS5501-9
16、for group I category “ia” systems. This standard is not applicable to mine telephone systems. NOTE 1Further requirements for intrinsic safety are specified in BS1259 and BS5501-7. NOTE 2The titles of the publications referred to in this standard are listed on the inside back cover. 2 Definitions For
17、 the purposes of this BritishStandard the following definitions apply. 2.1 loudspeaker communication system a system incorporating loudspeaker units enabling speech and other audio signals to be broadcast NOTEA typical system is shown in Figure 1. 2.2 loudspeaker unit a device normally comprising a
18、loudspeaker, microphone, amplifying/signalling circuits, and an internal power source 2.3 surface switchboard a manned control desk into which various separate underground loudspeaker communication systems may be extended to allow communication between underground and surface, and enable operator in
19、terconnection of separate systems 2.4 input impedance the electrical impedance presented to a received signal measured at the interconnection between systems 2.5 output impedance the electrical source impedance of a transmitted signal measured at the interconnection between systems 2.6 safety couple
20、r and safety barrier safety devices that are used to limit the transfer of electrical energy between interconnected systems 3 Electrical interface characteristics The electrical interface characteristics of the loudspeaker communication system and the surface switchboard system shall be as given in
21、Table 1. 4 Interconnection facilities 4.1 Each loudspeaker communication system shall include a safety coupler of the type specified in A.1, to allow the connection of audio signals to another loudspeaker communication system and/or to a surface switchboard. NOTEThe safety coupler should be incorpor
22、ated within the enclosure of one of the units forming part of the loudspeaker communication system. 4.2 The surface switchboard shall include safety barriers of the type specified inA.2 to allow the connection of audio signals to each underground loudspeaker communication system. If the surface swit
23、chboard is certified intrinsically safe, it shall include either safety barriers of the type specified inA.2 or safety couplers of the type specified inA.1. 5 Tone signals 5.1 General. Each system shall be designed to prevent the transmission of unwanted signals between systems. 5.2 Call tone. The c
24、all tone, which is used for calling the surface switchboard from underground loudspeaker communication systems, shall meet the following requirements. a) The amplitude shall be as given in Table 1. b) The waveform shall be sinusoidal. c) The frequency shall be either194Hz3% or5kHz3%. The surface swi
25、tchboard shall not respond to tones of less than1.5s duration and shall respond to tones of3.0s or more. 6 Transmission distance The system shall be capable of meeting the requirements of this standard over a distance of20km when using a cable of the type specified inAppendix B. BS6353:1983 2 BSI 12
26、-1999 Table 1 Electrical interface characteristics 7 Marking The apparatus providing network interconnection facilities shall be marked as specified in BS5501-9 together with the number of this BritishStandard, i.e.BS6353 1) . 8 Documentation The supplier of the equipment shall produce and make avai
27、lable such information as is necessary for the safe and correct use of the equipment. Electrical parameters (seeFigure 2) Underground loudspeaker communication system Surface switchboard Input impedance (Z i ) at1kHz 1507 minimum 1507 minimum Output impedance (Z o ) at1kHz 1507 maximum 1507 maximum
28、Input voltage levels (V i ) Minimum input speech level Minimum input call tone level: at194Hz at5kHz Input signal level to achieve nominalrated audio output Maximum input signal level 1V peak to peak 12V peak to peak b 0.10V peak to peak a 150mV peak to peak 30mV peak to peak 12V peak to peak b Outp
29、ut voltage levels (V o ) Minimum output speech level Nominal output speech level c Nominal output call tone level: at194Hz at5kHz Maximum output signal level 1V peak to peak into1507 6.5V peak to peak 2V peak to peak 12V peak to peak open circuit 1V peak to peak into1507 12V peak to peak open circui
30、t a The electrical characteristics relating to a surface switchboard need to differ from those of an underground loudspeaker system to take account of the considerable distance involved and consequent signal loss. b It is essential that this level does not damage the system, although some distortion
31、 of the audio output is permissible. c It is recognized that there will be a large variation in output levels from a particular system due to the indefinable speech input level to the system. The nominal level should be achievable under normal operation. 1) Marking BS6353 on or in relation to a prod
32、uct is a claim by the manufacturer that the product has been manufactured in accordance with the 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 to support such claims shoul
33、d be addressed to the Director, Quality Assurance Division, BSI, Maylands Avenue, Hemel Hempstead, Herts HP24SQ, in the case of certification marks administered by BSI, or to the appropriate authority for other certification marks.BS6353:1983 BSI 12-1999 3 Figure 1 Underground loudspeaker communicat
34、ion system Figure 2 System electrical parametersBS6353:1983 4 BSI 12-1999 Appendix A Design of safety couplers and barriers A.1 Safety couplers A.1.1 General. The safety coupler is intended to limit the voltage and current available in the interconnecting circuit between one loudspeaker communicatio
35、n system and another loudspeaker communication system or a certified surface switchboard under normal and fault conditions. It shall take the form shown in Figure 3 and be constructed in accordance with BS5501-7 for groupI category “ia” apparatus with the additional requirements specified inA.1.2 to
36、A.1.4. A.1.2 Transformer. The transformer shall be designed to provide adequate transmission of the speech and call tone frequencies. NOTEThe unprotected winding connected to the loudspeaker system may require additional safety devices. A.1.3 Zener diodes. The diodes shall be arranged back-to-back a
37、nd there shall be three such assemblies in parallel. Each diode shall have a manufacturers declared zener voltage of5.6V 5%. A.1.4 Resistors. Each resistor shall have a value not less than5.07. A.2 Safety barrier A.2.1 General. The safety barrier is intended to limit the voltage and current availabl
38、e in the interconnecting circuits between an uncertified surface switchboard and one or more loudspeaker communication systems. It shall take the general form shown in Figure 3, and shall be designed andconstructed in accordance with clause8 of BS5501-7 for group I category “ia” apparatus with the a
39、dditional requirements specified inA.2.2 toA.2.4. A.2.2 Transformer. The transformer shall be designed to provide adequate transmission of speech and call frequencies. A.2.3 Zener diodes. The diodes shall be arranged back to back and shall have a manufacturers declared zener voltage of5.6V5% and sha
40、ll be rated on the basis that no loss occurs in the transformer. A.2.4 Resistors. Each resistor shall have a value of not less than5.07. Appendix B Cable The cable to be used for assessment of system performance shall be a single twisted pair1.5mm 2telephone cable suitable for use up to110V between
41、cores. The conductors shall consist of plain annealed copper wires which shall comply with BS6360. Each conductor shall consist of seven wires of0.50mm diameter and shall be insulated with an extruded layer of PVC compound complying with BS6746 for type1 to give a minimum thickness of0.38mm at any p
42、oint and an overall diameter of2.36mm minimum and2.64mm maximum. The cable shall be bedded to a nominal thickness of0.8mm and be armoured. Figure 3 Safety couplerBS6353:1983 BSI 12-1999 5 Figure 4 Safety barrier6 blankBS6353:1983 BSI 12-1999 Publications referred to BS1259, Intrinsically safe electr
43、ical apparatus and circuits for use in explosive atmospheres. BS5501, Electrical apparatus for potentially explosive atmospheres. BS5501-7, Intrinsic safety “i”. BS5501-9, Specification for intrinsically safe electrical systems “i”. BS6360, Specification for conductors in insulated cables and cords.
44、 BS6746, PVC insulation and sheath of electrical cables. BS6353:1983 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK view on standards in Europe and at the international level.
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