Hot Circuit Detector


  • Protects miners from uncoupling live circuits
  • Protects mine motors from damage due to reverse sequence or single phase conditions
  • Maximizes mine production Features
  • Redundant phase voltage indication
  • Phase rotation indication (ABC OR CBA)
  • Loss of phase function trips the circuit
  • Reverse rotation function trips the circuit
  • Panel or coupler mounted
  • Self powered


Becker Mining America designed the Hot Circuit Detector 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

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 out the circuit. It also allows quick and easy determination of phase sequence (either ABC or CBA), and if reverse sequence can trip the circuit

The unit is available in 120vac or 480vac and can be configured with intermediate devices to monitor voltages up to 38KV. The unit is also available with a 240vac, 10amp normally open contact or fail safe contact. Note that fusing should be incorporated as required by MSHA.

Environmental Data

  • Opera ng Temperature –40degC to +85deg C
  • Storage Temperature –55degC to +100degC
  • Humidity 5% - 95%, non-condensing
  • Tripping Conditions
  • Low three Phase Voltage Detec on 50% of all three Phases A+B+C 5 seconds
  • Reverse Sequence
  • Led Indicators
  • Two Led Indicators for each Phase A, B, C
  • Phase Rota on Detec on 2 seconds from PowerUp Clockwise Rota on Counterclockwise Rotation
  • Flashing=Fail
  • Electrical Connections:
  • Phase A
  • Phase B
  • Phase C
  • Ground N.O. and N.C. Relay Contact Output Options

Part Numbers

  • DD 100-0117 480/575V N.C. model (fail safe)
  • DD 101-0275 480/575V N.O. model
  • DD 101-0594 120V N.C. model (fail safe)
  • DD 101-0595 120V N.O. model

Contact factory for additional configurations