Rating of automatic transfer switch

Status
Not open for further replies.

lfloyd

Member
On an optional standby system, can a 400amp transfer switch be used on a 600 amp service?
The normal and load feeders would be sized for 600 amps and the generator feeders would be rated for 400 and protected at the generator by a 400 amp breaker. It will transfer the entire service load.
The calculated load on the service is currently under 400 amps but has been sized for future loads.
Can this be done?
 

texie

Senior Member
Location
Fort Collins, Colorado
Occupation
Electrician, Contractor, Inspector
On an optional standby system, can a 400amp transfer switch be used on a 600 amp service?
The normal and load feeders would be sized for 600 amps and the generator feeders would be rated for 400 and protected at the generator by a 400 amp breaker. It will transfer the entire service load.
The calculated load on the service is currently under 400 amps but has been sized for future loads.
Can this be done?
You'll need to put a 400 amp OCPD ahead of the switch. The ATS has to be sized for the circuit it is installed in.
 
On an optional standby system, can a 400amp transfer switch be used on a 600 amp service?
The normal and load feeders would be sized for 600 amps and the generator feeders would be rated for 400 and protected at the generator by a 400 amp breaker. It will transfer the entire service load.
The calculated load on the service is currently under 400 amps but has been sized for future loads.
Can this be done?

best i know the answer is NO ...


if you are interupting the 600 amp service you need a 600 amp transfer switch ....
 
Status
Not open for further replies.
Top