DGMS (Tech) Circular 10 of 2026 — OEM spares in approved electrical equipment, and preserving flameproof and intrinsic safety protection

Summary

Addressed to owners, agents and managers of all mines. Electrical equipment used in hazardous areas is approved with specific methods of protection — flameproof (FLP) and intrinsic safety (IS) under the IS/IEC 60079 series — and that approval covers the equipment as a complete system, including components, sub-assemblies, protective circuits and safety-critical parts, subject to regulation 208(3) of the Coal Mines Regulations 2017. Inspections and manufacturer complaints found non-OEM, non-OPM and unauthorised spares fitted to DGMS-approved electrical equipment, including protective and control circuit devices such as relays, current transformers, interposing relays, contactors, sensors, electronic modules and associated devices. The circular warns that such substitution compromises the flameproof integrity of enclosures and the intrinsic safety protection philosophy, and directs that only OEM, OPM or authorised spares be used.