Switchboard dual breaker closed transition

[Live2learn]

I have two utility feeds from 1500kVA transformers that terminate in new switchboard with LVPCB

Also generator paralleling gear with 1200kVA worth of generator. The generators (3) sync up and parallel with each other and then terminate on new main switchboard.

The main question lies with a closed transistion return from gen to utility. My concern that this isn't a switchgear but a switchboard. It has LVPCB's and I have rated the fault current for the combination of both services. The sources will sync up inside the gear for 100ms or less with a make before break scenarion. I am also installing new relays for better control.

 

[rcw retired EE]

Do you have a specific question?

If all equipment is rated for the full short circuit of both services and both generators togehter and paralleling is done with an autosynchronzier supervised by synch check relays, you are probably OK. Verify the reaction time of the breakers. Soem switchboard types can't clsoe very qucikly, creating issues when synchronizing.

 

[Live2learn]

Not really just a little freaked and looking for that warm fuzzy feeling I enjoy, because I always used ansi rated switchgear for paralleling not UL 891 switchboard standards.

 

[dpc]

If you have electrically-operated LVPCBs and you've rated the breakers for the combined fault current, I think you will be OK. The non-drawout configuration makes maintenance a little tougher.

David Castor

http://www.cvoes.com