commercial back up generator

[techniphase]

Have an opportunity to get my first real commercial gig. A large commercial building w/400 amp 120/208 3 phase service. Meter and breaker switc gear located in electrical room on frst level. occupant says he has 3 sub panels located throughout the building and wants them on back up generator as well since they all run off same meter and main breaker. My question is, do they make a transfer switch that can be wired in at the main and keep the wholebuilding running or do i have to install 3 tranfer switches adjacent to every sub panel?

I am probably missing some key info so feel free to clear me up on this one.

 

[iwire]

If this is design / build there is a high potential to overlook something and loose money if you are not familiar with this work.

But yes you could get a transfer switch that could handle the entire service.

You need to confirm this generator is optional Article 702 or if it could be emergency Article 700. You have to know for sure as it changes a lot of things.