transfer switch sizing

[mcclary's electrical]

I have a customer with an 800 amp service and a 400 amp generator. Should the transfer switch be sized to fit the generator or the service?

 

[jim dungar]

I have a customer with an 800 amp service and a 400 amp generator. Should the transfer switch be sized to fit the generator or the service?

The transfer switch must be sized for the amount of current that will flow through it. If the normal source (protective device) feed to the switch is 800A then the switch needs to be sized for that amount.

 

[mcclary's electrical]

I feel the same way but I was just making sure because when they bought this generator it came with this switch,,,,,,,and as you know an 800 ap switch adds a HUGE amount to this bid,,,,,thanks

 

[jim dungar]

I feel the same way but I was just making sure because when they bought this generator it came with this switch,,,,,,,and as you know an 800 ap switch adds a HUGE amount to this bid,,,,,thanks

It is not a surprise that a 400A generator came with a 400 switch. I am sure the switch supplier was never told the size of the normal feed.

 

[mcclary's electrical]

I didn't say I was surprised????,,,,,there are four 200 amp panels fed indiviually from the ct cabinet. I decided I'm gonna grab two of those four feeds and take to t/switch. Thanks for being such a smarta**