Specification for mining type flameproof gate-end boxes. Gate-end boxes for drilling machines (for use on 3-phase a.c. circuits up to 650 V)|Electrical safety, Dry-type transformers, Protected electrical equipment, Gate-end boxes, Electrical protection equipment, Type testing, Power transformers, Rated current, Design, Endurance testing, Electric enclosures, High-voltage tests, Mining equipment, Drilling (mineral extraction), Rated voltage, Rated frequencies, Frequency changers, Transformers, Electric connectors, Temperature rise, Marking, Drilling machines