Generator Transfer Switch Sizing

[stacy young]

I have 800 Amp Main Service. My customer only wants to install generator on 200 Amps in the building. A 200 Amp breaker is present in the 800 Amp Panel that feeds a 200 Amp Panel in the building. What size transfer switch do I need to install?

 

[qcroanoke]

I have 800 Amp Main Service. My customer only wants to install generator on 200 Amps in the building. A 200 Amp breaker is present in the 800 Amp Panel that feeds a 200 Amp Panel in the building. What size transfer switch do I need to install?

Are you proposing putting the 200 amp panel on the load of the ATS?
If so you need to put the ATS between the 200 amp breaker in the 800 amp panel and the 200 amp panel.


If that is what you want to do you need a 200 amp transfer switch.