The Hot Circuit Detector is designed to protect the miner, prevent motor damage, and maximize production. Malfunctions such as a stuck contactor bottle or stuck mechanical contact can leave the motor circuit energized, undetected by the mine electrician.
Another anomaly is when a bottle or contact fails to close, resulting in single phasing and eventually damaging the motor. Also, if a circuit to a hydraulic motor or fan operates in reverse sequence this may result in dangerous or damaging consequences.
About the HCD
The device benefits the mine by providing indication and contactor/circuit breaker control when the voltage and/or phase rotation are not correct. The Hot Circuit Detector indicates that all phases are present, or if one or more phases are lost, it indicates which of the phases are missing and can trip