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What do the indication lights on the Micrologic trip units mean?

Product Line:
3-Phase, 600V, P and R Frame Breakers with Micrologic Trip Units


The Ir long-time pickup level was exceeded.

Isd/ Ii:  The Isd short-time pickup or the Ii instantaneous pickup was exceeded.

Ig:   The Ig ground fault pickup was exceeded.

Ap:   The self-protection indicator light (D) lights when the trip unit causes the breaker to trip
for a reason other than an overcurrent on the Ir, Ii, Isd, or Ig functions. 
The Ap light can indicate:
* issue with internal current sensors, usually moisture or corrosion
* instantaneous override level is exceeded
* fail-safe protection for circuit in case of trip unit malfunction
* trip unit temperature approaches 90 deg. C
* overvoltage on 24 Vdc inputs F1-F2

Related Links
FA FA176046: Determining the cause of breaker tripping with Ap light indication on the Micrologic trip unit
Instuction Bulletin 48049-136-05:  Micrologic 2.0A, 3.0A, 5.0A, and 6.0A Electronic Trip Units


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