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Is it OK to use a Powerpact or Masterpact breaker with ground fault trip unit on an ungrounded delta system?

Issue:
 Is it OK to use a Powerpact or Masterpact breaker with ground fault trip unit on an ungrounded delta system?  Because the system is ungrounded will using a GFI trip unit cause a problem?

Product Line:
Circuit Breakers

Environment:
Powerpact H J L  P R Masterpact NT NW

Resolution:
There are no negatives (except cost) to applying a Powerpact or Masterpact with integral ground fault protection on an ungrounded delta system.  Because the delta is ungrounded, a phase to ground contact will not result in current flow to ground and the breaker will not respond.  If another phase also had a ground fault there would be a phase to phase fault through ground which the breaker would respond to as a short circuit if the current was high enough.
The NEC reqirements in articles 210.13 and 230.95 are for ground fault protection on solidly grounded WYE systems with 150V or more to ground, and they say nothing about ungrounded delta.  So our recommendation is to not use breakers with LSIG trip units on ungrounded delta systems.
 
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