400 amp Auto Trans Switch install

[Poncho]

Currently have two 200 amp Dist Panels inside attached Garage 35 ft away from Service Entrance on far wall w/two 200 amp Breakers protecting the 35 ft wire. Being in the preliminary stages of installing a 22KW Generac w/a 400 amp ATS I'm curious as to the Indiana Code of placing the Switch up or down stream of said 200 amp Brkrs. Appreciate any feed back.

 

[Norcal01]

If ahead of the service disconnects the ATS will have to be rated as service equipment, if the feeders are 3-wire, they will have to be changed to 4-wire & grounding and neutrals separated, if the ATS does not have load shedding capabilities, it is going to get real expensive because per the NEC the gen is going to have to be sized for the entire load, it becomes a bit more affordable if some larger loads can be removed during a power failure.

 

[Sponsor]

 

[Poncho]

My install ($7K) is with in Budget but not Contractor price( $12K) an is rated full load 22KW. Thanks for the sound info.