1、BRITISH STANDARD BS 5067:1985 Specification for Flameproof transformers for use in mines UDC 622.005:621.314.2213.34BS5067:1985 This British Standard, having been prepared under the directionof the Mining and Quarrying Requisites Standards Committee, was published under the authority of the Board of
2、 BSI and comes into effect on 31July1985 BSI 10-1999 First published January1974 First revision July1985 The following BSI references relate to the work on this standard: Committee reference MQE/15 Draft for comment83/78987 DC ISBN 0 580 14478 X Committees responsible for this British Standard The p
3、reparation of this British Standard was entrusted by the Mining and Quarrying Requisites Standards Committee (MQE/-) to Technical Committee MQE/15, upon which the following bodies were represented: Association of British Mining Equipment Companies BEAMA Transmission and Distribution Association Heal
4、th and Safety Executive National Coal Board Amendments issued since publication Amd. No. Date of issue CommentsBS5067:1985 BSI 10-1999 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 General 1 3 Insulation and temperature rise 1 4 kVA Ratings 1 5 Voltages and connec
5、tions 1 6 Frequency 1 7 Voltage adjustment tappings 1 8 General design and construction 1 9 Lifting and anchoring of core 2 10 Removable covers 2 11 Wheels 2 12 Mounting flanges and terminals 2 13 Provision for cable terminations 7 14 Over-voltage protection and earthing 8 15 Marking and rating plat
6、es 8 Appendix A Information to be supplied by the purchaser with enquiry and order 10 Appendix B Earth fault protection 10 Figure 1 Example of a terminal marking plate showing standard items of information to be provided and their arrangement 1 Figure 2 Mounting flange at lower-voltage end of transf
7、ormer 3 Figure 3 Mounting flange at higher-voltage end of transformer (for voltages not exceeding6.6kV) 4 Figure 4 Mounting flange at higher-voltage end of transformer (for voltages exceeding6.6kV and up to11kV) 5 Figure 5 Equipment flange (for voltages not exceeding6.6kV) 6 Figure 6 Equipment flang
8、e (for voltages exceeding6.6kV and up to11kV) 7 Figure 7 Example of rating plate for flameproof transformer showing standard items of information to be provided and their arrangement 9 Figure 8 System b type earth fault protection circuit 11 Table 1 Clearance and creepage distances in air 7 Publicat
9、ions referred to Inside back coverBS5067:1985 ii BSI 10-1999 Foreword This revision of BS5067 has been prepared under the direction of the Mining and Quarrying Requisites Standards Committee. It extends the scope of the1974 edition to include higher voltages up to11kV. BS5067:1974 is superseded and
10、withdrawn. Transformers complying with this standard are suitable for Group I enclosures and may also be suitable for other groups of gases (seeBS4683-2 and BS229). NOTEFor the purposes of this British Standard, the IEC convention for expressing the symbol for the unit kilovolt amperes, i.e.kVA, has
11、 been used as this is in general use in the electrical industry, rather than the convention indicated in BS5775 (ISO31). Attention 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
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 follo
13、ws: Health and Safety Executive HSE (M) Certification Support Unit Harpur Hill Buxton Derbyshire SK179JN. 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 Sta
14、ndard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, pages1 to12, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporat
15、ed. This will be indicated in the amendment table on the inside front cover.BS5067:1985 BSI 10-1999 1 1 Scope This British Standard specifies design requirements for dry-type flameproof three-phase power transformers intended for use below ground in mines. This standard does not apply to transformer
16、s of the types covered by BS2538 1)and BS5126-4. Appendix A lists information to be supplied by the purchaser with the enquiry and order. NOTEThe titles of the publications referred to in this standard are listed on the inside back cover. 2 General Transformers shall comply with BS171 for the rating
17、 and performance of the main component within the flameproof enclosure, except where specifically modified or extended in this standard. 3 Insulation and temperature rise The insulation materials of components within the transformer enclosure shall comply with either classH or class C of BS2757. The
18、 temperature rise of any part of the external surface of the enclosure(s) shall not exceed60 C when the transformer is tested at normal continuous full load current with the rated primary voltage applied to the principal tapping as described in3.6 of BS171-2:1978. 4 kVA Ratings The three-phase kVA r
19、atings shall be one of the following: 50,150,300,500,750 and1000. 5 Voltages and connections 5.1 Voltages The no-load voltages shall be selected from the following: NOTESeeAppendix A for information that should be provided by the purchaser. 5.2 Connections The connections shall be either delta-star
20、or star-star, as designated by the symbols Dy11 or Yy0, respectively, in Figure5a of BS171-4:1978. 6 Frequency The designed frequency of operation shall be50Hz. 7 Voltage adjustment tappings The primary windings shall be provided with tappings at 5% and10% of the rated voltage in addition to the pri
21、ncipal tapping at the rated primary voltage. A readily accessible off-circuit selecting device, having the positions clearly marked, for example as shown in Figure 1, shall be provided to enable the tappings to be changed. 8 General design and construction 8.1 Flameproof construction Transformers sh
22、all comply with Group I enclosures of either BS4683-2 or BS5501-1 and BS5501-5. 1) Under revision. Nominal primary voltage: 3.3kV,6.6kV,11kV No-load secondary voltage: 565V,1130V, 3.4kV,6.8kV Figure 1 Example of a terminal marking plate showing standard items ofinformationtobeprovided and their arra
23、ngementBS5067:1985 2 BSI 10-1999 Transformers designed before the date of publication of this standard and certified as flameproof in compliance with BS229 for Group I enclosures shall be deemed to comply with this standard if they comply with all other requirements of this standard. 8.2 Materials T
24、he transformer enclosure shall be of mild steel. NOTE 1It is essential that enclosures should be substantially constructed sufficient to withstand rough conditions of handling, e.g.being slung or pushed into or out of cages, and being transported below ground. No part external to the flameproof encl
25、osure of any transformer shall be made of aluminium, magnesium or titanium, neither shall any alloy containing aluminium and/or magnesium and/or titanium be used unless the total content of these three constituents does not exceed15% by mass and the content of magnesium and titanium together does no
26、t exceed6% by mass. No component external to the flameproof enclosure shall be painted or coated with preparations containing, in metallic form, aluminium, magnesium or titanium. NOTE 2These limitations have been imposed to avoid the hazards of incendive sparking due to friction between rusted steel
27、 or iron and the metals in question. 8.3 Lifting Six lifting lugs shall be provided on the enclosure body, i.e.four for normal lifting and two at one end for lowering the transformer on end down a shaft. At least four shackles complying with BS3032 shall be fitted. Each lug and shackle shall be of s
28、ufficient strength to support the whole weight of the transformer, complete with its ancillary equipment, when slung by any one lug. Means shall also be provided for the attachment of haulage chains to the fender or to the base of the tank or enclosure. 8.4 Drainage Any drainage devices supplied to
29、release condensed moisture shall comply with8.1 in all positions between, and including, fully opened and fully closed. 9 Lifting and anchoring of core The core and winding assembly shall be provided with means for attaching withdrawal and/or lifting tackle. Means shall also be provided to ensure co
30、rrect registration of the core in the enclosure, and to prevent movement of the core and windings when the enclosure is on its side or end. 10 Removable covers Each removable door or cover which gives access to an enclosure containing live components, including those with any neutral link, shall car
31、ry the warning: “OPEN HV ISOLATOR BEFORE REMOVING THIS COVER”. This warning shall either be embossed on the door or cover, or be of indelible lettering on a metal plate permanently secured to the door or cover. 11 Wheels If wheels and axles are to be fitted, provision shall be made for the mounting
32、of axles fitted with flanged wheels having a tread diameter of305mm. The design of the wheel mounting shall provide for adjustment so that the clearance between rail level and the lowest part of the transformer can be set at either25mm or127mm. NOTE 1SeeAppendix A for information that should be prov
33、ided by the purchaser concerning the provision of wheels and axles. The track gauge shall be as specified by the purchaser. NOTE 2It is preferred that the wheels and axles be arranged to fit track gauges within either of the ranges457mm to769mm or610mm to922mm, increasing in each range by increments
34、 of13mm. 12 Mounting flanges and terminals 12.1 Mounting flanges Mounting flanges shall be provided on the ends of transformers having ratings of150kVA and above in accordance with a), b) or c) as follows: a) lower-voltage end flange as shown in Figure 2; b) higher-voltage end flange as shown in Fig
35、ure 3 for transformers having primary voltages not exceeding6.6kV; c) higher-voltage end flange as shown in Figure 4 for transformers having voltages exceeding6.6kV and up to11kV. NOTEThe mating equipment flanges are shown in Figure 5 and Figure 6.BS 5067:1985 BSI 10-1999 3 Figure 2 Mounting flange
36、at lower-voltage end of transformerBS 5067:1985 4 BSI 10-1999 Figure 3 Mounting flange at higher-voltage end of transformer (for voltages not exceeding6.6kV)BS 5067:1985 BSI 10-1999 5 Figure 4 Mounting flange at higher-voltage end of transformer (for voltages exceeding6.6kV and up to11kV)BS5067:1985
37、 6 BSI 10-1999 12.2 Terminals The form and positioning of terminal posts and their bushings shall be as shown in Figure 2, Figure 3 or Figure 4; see also12.1 a), b) and c). The terminal posts shall be of copper complying with BS1433 and shall have the following thread sizes, as designated in BS3643,
38、 according to their current rating. Lower-voltage end: up to and including315 A; M12 over315 A up to and including630 A; M20 2.0 Higher-voltage end: all current ratings; M12 The dimensions of hexagon nuts shall comply with BS3692 for the appropriate thread diameter. For terminals up to and including
39、12mm diameter, one normal thickness nut and one thin nut shall be used; for sizes above12mm diameter, two thin nuts shall be used. The nuts shall be of brass complying with BS2874. The tolerance class for terminal nuts and posts shall be grade6H and grade6g respectively as specified in BS3643. Figur
40、e 5 Equipment flange (for voltages not exceeding6.6kV)BS5067:1985 BSI 10-1999 7 12.3 Clearance and creepage The clearance and creepage distances in air shall be not less than the values given inTable 1. Insulating materials shall have a comparative tracking index of not less than250when tested as de
41、scribed in BS5901. Table 1 Clearance and creepage distances in air 13 Provision for cable terminations The transformer terminals shall be contained in an air-filled enclosure. NOTE 1This may be a separate terminal chamber or may fulfil additional functions, i.e.form part of a high voltage circuit br
42、eaker or a chamber for housing protective equipment at the lower-voltage end of the transformer. The terminal chamber, or the equipment of which it forms part, shall be suitable for fitting to the appropriate flange as shown in Figure 2, Figure 3 and Figure 4. The terminal chamber or the equipment c
43、omprising part of the chamber shall be provided with facing(s) to receive cable sealing boxes or cable coupler adaptors. The facing shall comply with the appropriate British Standards. Up to 1130V Up to 6.8kV Up to 11kV Clearance, phase to phase Clearance, phase to earth Creepage, phase to earth mm
44、25 25 32 mm 74 55 74 mm 127 76 127 Figure 6 Equipment flange (for voltages exceeding6.6kV and up to11kV)BS5067:1985 8 BSI 10-1999 Cable glands and sealing boxes, where fitted, shall comply with BS542. NOTE 2The cable coupler adaptors should be those covered by the following British Standards: BS3454
45、 for voltages up to3.3kV BS3905 for voltages up to6.6kV. Cable terminations shall be so arranged that cables fitted with cable sealing boxes or other similar fittings can be disconnected and detached from the transformer without disturbing the sealing compound, without exposing the interior of the t
46、ransformer enclosure(s), and without the bushings having to be moved. NOTE 3Where switchgear is fitted, cable entry may be limited to one direction only. If required by the purchaser, the manufacturer shall provide covers for the physical protection of the terminals and bushings when a removable typ
47、e terminal chamber is not in position (seeAppendix A). Cable couplers that are certified as flameproof may not, when used singly, have the necessary current rating to carry the output of the larger sizes of transformer. In such cases, more than one outlet shall be provided with suitable overcurrent
48、protection for each circuit. 14 Over-voltage protection and earthing 14.1 General Provision shall be made for protection against danger arising from the charging of the lower-voltage components by contact with, or leakage from, higher-voltage components. To assist in complying with this requirement,
49、 provision shall be made for the connection to earth, where necessary, of the neutral point of the secondary winding. NOTEInformation on earth fault protection systems is given in Appendix B. 14.2 Provision for earthing neutral point of secondary winding The neutral point of the secondary winding shall be brought out to an insulated terminal. An earth terminal shall be provided at the lower-voltage end of the transformer, either in the lower-voltage chamber (seeB.5) or in such other fitment as shall be ordered by the purchaser for the
