sec.29Operating times and tripping current for circuit protection devices

### sec.29 Operating times and tripping current for circuit protection devices A coal mine’s electrical engineering manager must ensure each circuit protection device at the mine has an appropriate operating time and tripping current, having regard to a risk assessment of the operation of the part of the electrical installation the device protects. For a surface mine, the operating time may allow for a delay in cutting off the electricity supply if— the device is installed to protect a person operating equipment; and it is appropriate to allow the person to bring the equipment to rest before the electricity supply is cut; and the person is immediately given a clear warning of the fault. (sec.29-ssec.1) A coal mine’s electrical engineering manager must ensure each circuit protection device at the mine has an appropriate operating time and tripping current, having regard to a risk assessment of the operation of the part of the electrical installation the device protects. (sec.29-ssec.2) For a surface mine, the operating time may allow for a delay in cutting off the electricity supply if— the device is installed to protect a person operating equipment; and it is appropriate to allow the person to bring the equipment to rest before the electricity supply is cut; and the person is immediately given a clear warning of the fault. - (a) the device is installed to protect a person operating equipment; and - (b) it is appropriate to allow the person to bring the equipment to rest before the electricity supply is cut; and - (c) the person is immediately given a clear warning of the fault.