• In a Main-Tie-Main system, the main breaker cannot be short time ZSI restrained by the tie breaker.
• Since the main circuit breaker cannot be restrained on short time, it must be ZSI self restrained on the short time function.
• The main circuit breaker can be ground fault restrained by the feeder breakers.
• Installation of GF ZSI has no effect on MDGF and MDGF has no effect on GF ZSI.

Released for: Schneider Electric Canada