28 September 2021
Micrologic Series B breaker trips on low currents without an indication on the LCD display.Product Line:
LE LX LXI ME MX NE NX PE PX SE circuit breakersEnvironment:
Electrical Distribution SystemsCause:
Need to determine the cause of trippingResolution:
There are a number of possible reasons for a circuit breaker to trip without indication.
1. First, check for proper wiring and operation of the control circuits (if present).
2. If there is no shunt trip or UVR, or if proper signals are verified, we must assume the trip unit is bad, and the breaker must be replaced.
In the case of the SE circuit breaker only, a replacement trip unit may be available. Check the Supplemental Digest for availability.
Replacement trip units never were available for the other Series B Micrologic breakers.