Is it possible to use the Micrologic trip unit on a Powerpact or Masterpact circuit breaker to provide phase loss, phase reversal, or phase imbalance protection?
Is it possible to use the Micrologic trip unit on a Powerpact or Masterpact circuit breaker to provide phase loss, phase reversal, or phase imbalance protection? Might be specifically looking at the Power and Harmonic Micrologic trip units, which have some features that seem similar to phase loss proteciton
Molded Case Circuit Breakers, Insulated Case Circuit Breakers, Phase Failure Relays
While the Power and Haromonic trip units do have some voltage protection features, they cannot be used as phase loss protection as neither the minimum voltage protection or voltage unbalance protection can detect the loss of a phase or phases.
For phase loss protection here is what is required:
- Circuit breaker or switch that accepts electrical accessories
- Phase Measurement Relay with desired features
- Shunt trip that matches the Phase Measurement Relay's control voltage
An undervoltage relay could be used to detect a total power loss or drop, but it would at most be able to monitor voltage on two phases. If there was a voltage loss/drop on the third phase, the undervoltage trip would be unable to detect it.