which contactor?

[hardworkingstiff]

I'm looking at a marina that want's to do some remodeling. I have to modify 3, 100-amp 120/240V circuits (so as to not have to pull new feeders onto the dock). The AHJ has said he will not require (555.3) upgrade to anything we do not modify. In other words, the (2) 800-amp MB panels will not be required to have the GFP installed on them, just the 3 circuits we modify.

I've found a product that looks pretty good for the GF monitoring (here), but I need to get the disconnecting in place. I could order some shunt trip breakers, or the person at Bender I was talking to suggested installing contactors. If I go the contactor route, what would hold up the best to 24/7/365 on position (mounted in a 3R box outdoors)?

I've never liked shunt trip breakers because if the control system fails, the protection is gone. I guess I could install some NC control relays that would send a signal to the shunt trip breaker if the control voltage is lost, but the only way I know to do that is to get the voltage from the 100-amp breaker itself. Are you allowed to come off of a 100-amp breaker through a control relay and then back to the shunt trip part of the breaker (edit: w/out installing overcurrent protection)?

 

[hillbilly1]

I'm looking at a marina that want's to do some remodeling. I have to modify 3, 100-amp 120/240V circuits (so as to not have to pull new feeders onto the dock). The AHJ has said he will not require (555.3) upgrade to anything we do not modify. In other words, the (2) 800-amp MB panels will not be required to have the GFP installed on them, just the 3 circuits we modify.

I've found a product that looks pretty good for the GF monitoring (here), but I need to get the disconnecting in place. I could order some shunt trip breakers, or the person at Bender I was talking to suggested installing contactors. If I go the contactor route, what would hold up the best to 24/7/365 on position (mounted in a 3R box outdoors)?

I've never liked shunt trip breakers because if the control system fails, the protection is gone. I guess I could install some NC control relays that would send a signal to the shunt trip breaker if the control voltage is lost, but the only way I know to do that is to get the voltage from the 100-amp breaker itself. Are you allowed to come off of a 100-amp breaker through a control relay and then back to the shunt trip part of the breaker (edit: w/out installing overcurrent protection)?

They do make a capacitive backup power supply for shunt trip breakers, that could be another solution.