GE breaker zone interlock

[PWR]

I have searched in vain on the GE website for the answer to this question: If you have current production MVT Plus trip units on their Wave Pro or Power Break II low voltage breakers, and you have one of the two zone interlocking options, and you wish to defeat the zone interlocking feature, how do you accomplish that?

 

[rbulsara]

Here is the response I had received from GE tech/engineer, for one of our projects as couple of yrs ago.

"Just a little clarification, If the ZSI (assuming Z1, ground fault only)wiring is not connected the ground fault protection will operate on the number one band no matter which band the programmer is set on. For example, if the main is set on delay band three and the ZSI wiring remains unconnected the programmer will trip on a band one setting. If ZSI is in use (wiring connected) the breaker programmer closest to the fault in the ZSI protective scheme will trip on band one. Per the product owner there is no instantaneous tripping on ground fault with or with out ZSI.

Again, the only way to eliminate this function is to replace / reprogram the breaker programmers. "

Hope that helps..Good luck

 

[alehman]

Slightly off-topic: I recently addressed this question for Cutler-Hammer DS/DS2 breakers. They simply go to minimum time delay if the ZSI terminals are open. For phase faults the short time delay goes to minimum. For ground faults, the ground delay goes to minimum. ZSI can be effectively disabled (forcing normal delay bands) by jumpering the ZSI wiring terminals on the breaker.

 

[PWR]

Eaton C-H did it logically: put the restraint signal "out" right back into the restraint signal "in" on the same trip unit (via jumpers) and you have defeated zone interlock. GE apparently applies a 3 VDC signal from a separate module in each zone as the restraint signal. I'm thinking at a minimum you can wire the breakers on the upstream side of the module as downstream breakers and they will be restrained at least in a one zone setup.