400A Main Breaker is tripping

[ptonsparky]

Along with what COW said, have your supplier price a whole new unit as if it were a new project complete with all new breakers. The prices come down considerably when they know they are bidding.

 

[electrofelon]

the replacement that squareD quoted came in at $19k.

I try not to purchase large framed breakers directly from the manufacturer unless someone is holding a gun to my head. Their markups are insane once they know you have their gear installed and you need parts for it. I don't like those games.

I try 3rd party resellers/testing firms, whether it's new or used/tested surplus first. If that doesn't pan out, then I head over to the manufacturer knowing what comes next, is going to be sticker shock.

20k for a 400 amp breaker is nowhere near reasonable.

I was quoted about 20k from Square D for a replacement for an obsolete breaker. That was 1000 amp, but sill absurd IMO. Not saying that the other guys wouldnt do the same thing, but that ticked me off and is one of the reasons I avoid square D like the plague now. Ripped the whole 3 section thing out of there, sent to china for scrap, turn into filing cabinets - except for the copper busbars which I kept to make something cool out of maybe a shelf or a hanger for pots and pans.....

 

[zog]

Thank you for the responses everyone. We have a breaker testing and rebuild shop on site so I'm gonna look at getting the panel on a temporary generator while we pull the breaker and test it. If the breaker ends up being faulty I will definitely be looking into replacing it with a set of fuses, another panel, or seeing if i can find an adapter kit to make a different breaker fit since the replacement that squareD quoted came in at $19k. Zog I appreciate your offer on the repair but unfortunately my employer will not let us repair(or have anyone else repair) molded case breakers.

It's not a breaker repair , it's a trip unit repair, or you can replace the trip unit with a new one. A new replacement for that breaker (PJA) should be around $5k (19k is insane)

 

[jim dungar]

It's not a breaker repair , it's a trip unit repair, or you can replace the trip unit with a new one. A new replacement for that breaker (PJA) should be around $5k (19k is insane)

They probably do not need a 1200A frame breaker for a 350A load. 29 years ago the smallest electronic trip available would have been the ME family. Now you can get them in Powerpact L 600A frame sizes.
The only issue is how the main breaker is actually installed. If it is connected to the I-Line bussing like any branch breaker, then the OP can use any 350A trip breaker they want. However, if the breaker was connected to the in-line with the I-line stack, like a traditional main device, they will need to replace it with a similar device, or replace the panel interior.