BS 787-1:1969
Specification for mining type flameproof gate-end boxes. Gate-end boxes for direct-on-line motor starting (for use on 3-phase a.c. circuits up to 650 V)
For boxes with a range of three current ratings, having air-break electrically operated contactor which, with associated equipment, provides for control and protection of coalface machinery. Design and construction; attachment of cables; coupling of units; means of isolation; main contactor; test methods.