Technical FAQs

Ask a Question

Can a Micrologic Series B trip unit be changed or replaced?

Issue:
Can a Micrologic series B (or older) trip unit on a legacy breaker be replaced, changed, or upgraded in the field?

Product Line:
LX, LXI, LE, MX, ME, NX, NE, PX, PE, and SE circuit breaker frames

Environment:
Electrical Distribution Systems

Cause:
Need to add ground fault sensing to existing breaker or replace bad trip unit

Resolution:
The SE trip units can be changed by Field Services (see Supplemental Digest for availability).  
The ground fault function cannot be added to or deleted from an SE breaker.
A replacement trip unit may be installed ONLY in the breaker it is identified for.

The other breakers with Micrologic Series B and earlier trip units CANNOT be replaced.  These include LE, LX, LXI, ME, MX, NE, NX, PE, and PX type breakers.
Was this helpful?
What can we do to improve the information ?