1、BRITISH STANDARD BS 5125:1990 Specification for 50A 650V flameproof, restrained and bolted plugs and sockets for use in coal mines UDC 622.005:621.316.541.1-213.34BS5125:1990 This British Standard, having been prepared under the directionof the Mining and Quarrying Requisites StandardsPolicy Committ
2、ee, waspublished under the authorityof the Board of BSI andcomes into effect on 31July1990 BSI 11-1999 First published August 1974 Second edition July 1990 The following BSI references relate to the work on this standard: Committee reference MQE/14 Draft for comment 87/71282 DC ISBN 0 580 18482 X Co
3、mmittees responsible for this British Standard The preparation of this British Standard was entrusted by the Mining and Quarrying Requisites Standards Policy Committee (MQE/-) to Technical Committee MQE/14, upon which the following bodies were represented: Association of British Mining Equipment Com
4、panies British Cable Makers Confederation British Coal Corporation Council for Electrical Equipment for Flammable Atmospheres (BEAMALtd.) Health and Safety Executive Institution of Mining Electrical and Mining Mechanical Engineers Institution of Mining Engineers Rotating Electrical Machines Associat
5、ion (BEAMA Ltd.) Transmission and Distribution Association (BEAMA Ltd.) Amendments issued since publication Amd. No. Date CommentsBS5125:1990 BSI 11-1999 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 Definitions 1 3 Metallic components 1 4 Insulation 2 5 Contacts
6、2 6 Terminals 2 7 Plug 2 8 Socket 3 9 Retaining device 3 10 Closer cap for bolted socket 3 11 Dimensions 4 12 Flameproof enclosure 4 13 Type tests 4 14 Routine tests 6 15 Marking 6 Appendix A Information to be provided with enquiry and order 15 Figure 1 Bolted plug 7 Figure 2 Bolted socket 8 Figure
7、3 Restrained plug 9 Figure 4 Restrained socket 10 Figure 5 Bolted plug and socket assembly 11 Figure 6 Restrained plug and socket assembly 12 Figure 7 Closer cap for bolted socket 13 Figure 8 Associated mounting flange 14 Table 1 Properties of electrical insulating materials 2 Table 2 Contact tube c
8、onditioning data 5 Publications referred to Inside back coverBS5125:1990 ii BSI 11-1999 Foreword This revision of BS 5125 has been prepared under the direction of the Mining and Quarrying Requisites Standards Policy Committee. It supersedes BS5125:1974 which is withdrawn. This revision updates the s
9、pecification to reflect todays usage of 50 A restrained and bolted plugs and sockets designed primarily for equipment used in mining. Due cognizance has been taken of the relevant requirements of BS 4683-2 and BS 5501-5. This standard is designed to ensure interchangeability of plugs and sockets of
10、different makes, and to standardize the fixing dimensions of sockets; it specifies some electrical and mechanical requirements but does not purport to provide a fully detailed design. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standard
11、s are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Attention is drawn to the Health and Safety at Work etc. Act 1974, the Mines and Quarries Act 1954, the Regulations made under these Acts, and also any other
12、 appropriate statutory requirements or bye-laws. These place responsibility for complying with certain specific safety requirements on the manufacturer and the user. The address of the recognized certification authority in the UK for Group I (coal mining) apparatus for flameproof purposes is as foll
13、ows. Health and Safety Executive HSE (M) Certification Support Unit Harpur Hill Buxton Derbyshire SK17 9JN Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1 to 16, an inside back cover and a back cover. This standard has been updated (see copyright
14、 date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS5125:1990 BSI 11-1999 1 1 Scope This British Standard specifies the dimensional and test requirements for 50 A flameproof restrained and bolted plugs and sockets suitable for vo
15、ltages not exceeding 650 V, primarily intended for use with mining apparatus which is connected to its power supply by means of a flexible cable. These plugs and sockets incorporate three power contacts, one pilot contact for electrical interlocking, and a scraping earthing contact. Provision is als
16、o made for cable couplers, to enable lengths of flexible cable to be coupled together. NOTE 1The figures in this standard show only those essential features and dimensions for function and interchangeability. NOTE 2Appendix A lists the information to be supplied by the purchaser. NOTE 3The titles of
17、 publications referred to in this standard are listed on the inside back cover. 2 Definitions For the purposes of this British Standard the following definitions apply. 2.1 plug and socket a device consisting of two portions having metallic contacts and arranged to engage with each other, so forming
18、 a ready means of connecting or disconnecting current-using apparatus to or from the source of electrical supply 2.2 flameproof plug and socket a plug and socket which, when its parts are properly assembled together with the cable attached, complies with the relevant flameproof requirements 2.3 rest
19、rained plug and socket a plug and socket in which the two portions are engaged, retained and disengaged by means of a screwed union-ring 2.4 bolted cable plug and socket a plug and socket designed to be held together by two or more bolts or screws, or studs and nuts, in such a way that the plug and
20、socket cannot be disengaged without the use of a tool 2.5 plug that portion of a plug and socket having contacts consisting of tubes and which is attached to a flexible cable 2.6 socket that portion of a plug and socket having contacts consisting of pins and which is designed for the insertion and e
21、ngagement of a plug 2.7 fixed socket a socket incorporating a flange for attachment to associated apparatus 2.8 coupler socket a socket which embodies a cable gland for attachment to a flexible cable 2.9 cable coupler an assembly of a plug and a coupler socket 2.10 scraping earthing contact a device
22、 to ensure electrical continuity of the earthing connection between a plug and socket 2.11 cable gland a device designed to secure the end of a cable by means appropriate to the type of cable, and which may include provision for making electrical connection to any screen or metallic covering 2.12 cl
23、oser cap a cap primarily intended for blanking off motor sockets (see note to clause 10) 3 Metallic components The material for external components and enclosures shall be one of the following: a) a corrosion resistant ferrous alloy; b) a non-ferrous metal, other than aluminium, magnesium or titaniu
24、m; c) an alloy containing the metals aluminium, magnesium, titanium, either singly or in combinations, providing that the total content of these three constituents does not exceed15%(m/m) of the alloy and the combined content of magnesium and titanium does not exceed 6% (m/m) of the alloy. No compon
25、ent part shall be painted or coated with preparations containing, in metallic form, aluminium, magnesium or titanium. NOTEThese limits have been imposed to avoid the hazards of incendive sparking due to friction between rusted steel or iron and the metals in question.BS5125:1990 2 BSI 11-1999 4 Insu
26、lation 4.1 Insulation materials Properties of materials for electrical insulating components shall comply with Table 1. 4.2 Insulators Insulators shall be free from voids, cracks and deleterious inclusions and shall comply with 13.8. 5 Contacts Each plug and socket shall be provided with three power
27、 contacts and one auxiliary contact, i.e.contact tubes or contact pins, as appropriate, arranged as shown in Figure 1 to Figure 4. NOTEProvision for one of the power contacts and/or the pilot contact may be omitted from a bolted socket, subject to compliance with all other requirements of this stand
28、ard. 6 Terminals 6.1 General Terminals shall be bored to suit the size of cable to be used and shall be capable of being bored to a maximum diameter of 8 mm. For applications where the cable size is not given, terminals shall be bored to a diameter of 6 mm. Terminals shall be integral with contact t
29、ubes and contact pins. NOTEThis does not preclude the use of dissimilar metals for contact and terminals. Where screws are used as the clamping device on a terminal, not less than two such screws shall be provided and they shall be flat point hexagon socket screws complying with BS 4168. Each termin
30、al shall provide for the entry of the conductor to a minimum depth of 15 mm. 6.2 Earthing Earthing terminals shall be provided in the plugs and shall be capable of securely accommodating conductors of 6 mm 2to 25 mm 2cross-sectional area. Additional terminals shall be provided to accommodate securel
31、y any metallic screens. 7 Plug 7.1 Case The general dimensions of the case of the plug shall be as given in Figure 1 or Figure 3 andFigure 5or Figure 6 as appropriate. The engaging portion of the case of the plug which protects the contact tubes shall be of metal having a tensile strength of not les
32、s than 450 N/mm 2when determined in accordance with BS 18. The remaining portion of the case shall be of metal having a tensile strength of not less than225 N/mm 2 . The external surface of the engaging portion of the plug casing shall form part of a scraping earthing contact and shall be electrical
33、ly continuous with the remainder of the plug casing (see 8.3). 7.2 Contact tubes (power and pilot) The dimensions of the tubes shall be as shown in Figure 1 or Figure 3 as appropriate, and when assembled they shall be self-adjusting to the extent necessary to accommodate at least the permitted toler
34、ances on position shown in Figure 1 or Figure 3. Contact tubes shall be of any suitable metal having: a) a hardness of not less than 70 HB when determined in accordance with BS 240; b) a volume resistivity of not more than117cm at a temperature of 20 C. Table 1 Properties of electrical insulating ma
35、terials Property Value Test method Electric strength (90 C) 8 kV/mm (min.) BS 2782-2, method 220 or 221 a Volume resistivity 1 10 137cm (min.) BS 2782-2, method 230A b Tensile strength 34.5 N/mm 2(min.) BS 2782-3, method 320D Flexural strength 60 N/mm 2(min.) BS 2782-3, method 335A Impact strength 1
36、0 kJ/m 2(min.) BS 2782-3, method 359 Water absorption c 50 mg (max.) BS 2782-4, method 430A Comparative tracking index c CTI 400 (min.) BS 5901 Oxygen index 28% (min.) BS 2782-1, method 141 NOTE1 N/mm 2= 1 MPa. a Also numbered BS 903-C4. b Also numbered BS 903-C2. c Preparatory to any testing for th
37、ese properties remove not less than 0.5 mm by machining from all the surfaces of the test specimen and then finish smoothly.BS5125:1990 BSI 11-1999 3 Contact tubes shall make good electrical contact with the pins when the plug is inserted in the socket and shall comply with 13.2, 13.3 and 13.4. 7.3
38、Cable glands A cable gland shall be provided, suitable for the size and type of cable to be accommodated, up to a maximum overall diameter of 55 mm. Cable glands shall be of the compression type and shall be provided with the following: a) the means to comply with the relevant requirements of BS 550
39、1-5 for flameproof cable entries; b) the means to secure the cable; c) the means to seal the assembly against ingress of moisture. Where a pliable wire armoured cable is to be accommodated in the gland, a device shall be provided to clamp the armour wires in such a way that a good electrical connect
40、ion is made to the casing. NOTE 1Where non-metallic screens in direct contact with the earthing conductor are incorporated in a cable, it is not necessary to connect these screens to the additional terminals provided in accordance with 6.2. NOTE 2The following types of cable are normally employed: a
41、) flexible cable with individually screened power cores; b) flexible cable with collectively screened cores; c) pliable wire armoured flexible cable with or without individually screened power cores. NOTE 3The purchaser should state in the enquiry or order the type of cable to be accommodated in the
42、 cable gland (seeAppendix A). 8 Socket 8.1 Case The case of the socket shall be of metal having a tensile strength of not less than 225 N/mm 2when determined in accordance with BS 18 and shall have the general dimensions shown in Figure 2 or Figure 4 and Figure 5 or Figure 6 as appropriate. 8.2 Cont
43、act pins (power and pilot) Contact pins shall be solid and of any suitable metal having: a) a hardness of not less than 70 HB determined in accordance with BS 240; b) a volume resistivity of not more than117cm at a temperature of 20 C. Contact pins shall comply with the dimensions in Figure 2 and Fi
44、gure 4. 8.3 Scraping earthing contact The earth continuity circuit between a plug and socket shall be made by contact between the external surface of the engaging portion of the plug casing and the internal surface of scraping contacts mechanically attached and electrically connected to the socket c
45、asing. The contact shall comply with 13.9. The design shall be such that the earthing contact shall be made before the power contact pins and tubes come into contact and shall not be broken until the contact pins and tubes have separated. 9 Retaining device 9.1 Restrained type Of the two portions, i
46、.e. the plug, and the socket or coupler socket, arranged to engage with each other, the plug shall be provided with an internally threaded union-ring capable of rotating on it but not readily detachable from it, and the socket or the coupler-socket shall be provided with an external thread suitable
47、to take the thread of the screwed union-ring. The construction shall be such that the contact pins and contact tubes of the two portions do not come into contact until the union-ring has at least three threads in engagement. NOTEThe union-ring thus forms an operating and retaining device for engagin
48、g and disengaging the two portions. Particulars of the union-ring on the plug and the external threads on the socket are shown in Figure 3 and Figure 4 respectively. The ring shall be drilled with two 9 mm diameter holes positioned diametrically opposite to each other to enable a padlock to be fitte
49、d. 9.2 Bolted type Both portions arranged to engage with each other shall be provided with an external flange, the plug portion shall have clearance holes and the socket portion tapped holes, suitable for taking securing screws. The external flange of the plug portion shall be provided with the means for shrouding the socket heads of the securing screws. The dimensions of the coupling screws, also the dimensions and positions of the holes and of the means of shrouding, shall be as shown in Figure 1 and Figure 2. 10 Closer cap for bolted socket T
