Main Breakers

[sgunsel]

I am looking at a small demolition/refurbish project. There were 5 services, all 120/240 signgle phase, now there will be one. Two existing panels (former apartments, now to be offices) with 100 amp main breakers will become secondary panels, fed from a new main panel. Is it permissible to use a 100 amp breaker in the main panel to feed the subpanels that also have 100 amp main breakers? The distances are more than 25 feet.

 

[Volta]

I am looking at a small demolition/refurbish project. There were 5 services, all 120/240 signgle phase, now there will be one. Two existing panels (former apartments, now to be offices) with 100 amp main breakers will become secondary panels, fed from a new main panel. Is it permissible to use a 100 amp breaker in the main panel to feed the subpanels that also have 100 amp main breakers? The distances are more than 25 feet.

Yes. The sub-panel mains can remain, but the neutrals and grounding conductors will need to be separated, if not already.

 

[mcclary's electrical]

I am looking at a small demolition/refurbish project. There were 5 services, all 120/240 signgle phase, now there will be one. Two existing panels (former apartments, now to be offices) with 100 amp main breakers will become secondary panels, fed from a new main panel. Is it permissible to use a 100 amp breaker in the main panel to feed the subpanels that also have 100 amp main breakers? The distances are more than 25 feet.

It depends, they may have used the residential chart to size the feeders last time, If they did, you will not have enough feeder for 100 amp office panel. The feeders will need to be chaged to SER or add neutral if conduit anyway, so you can put whatever size panel you want.