Can ground fault be defeated, turned off, or removed from LX, LE, MX, ME, NX, NE, PX, PE, or SE circuit breakers that use a Micrologic Series B Trip Unit?
Circuit Breaker types LX, LE, MX, ME, NX, NE, PX, PE, SE, with Micrologic Series B Trip Unit
There are two parts to this answer:
(1) During normal use (not testing), the ground fault function cannot be defeated, turned off, or removed from these breakers. This is a permanent function of the Micrologic Trip Unit, and is therefore an integral part of the breaker. If it is necessary to reduce ground fault trip sensitivity, the ampere pickup value and the time delay can be adjusted to higher values by using the dials on the trip unit. On SE breakers ONLY, the ground fault trip unit can be changed for a ground fault alarm trip unit (no trip). Availability is very limited, and the work must be done by our Field Services. Contact us if you have questions.
(2) During primary injection testing only, the "looping" method can be used to temporarily eliminate a ground fault trip for the duration of the test. SE breakers have an additional method to use during a test. These methods cannot be used during normal breaker operation. See bulletin 0600IB1201 for those details.