circuit protection before or after transfer switch

[boomer3]

I am building a system that is mobile and will have the possibility of two feeds.
1.Shore power at 240 vac (300amps)
2.Shore power at 480 amps (150 amps)

I have circuit protection before and after the "on board" step up xformer on the 240 vac feed. I also have circuit protection at the feed for the 480 vac entrance.

I am using a manual transfer switch to give the choice of 480 vac or 240 vac shore power.

Can I use a single CB after the transfer switch instead of having an individual CB for each feed before the transfer switch? Both feed will be 480 vac at this point.

My normal practice is to have an external connection see a circuit breaker before anything else in the trailer. I also normally protect the secondary of the transformer before it goes elsewhere. I don't see anything in article 230 addressing this.

Thanks, and God Bless...

 

[templdl]

Re: circuit protection before or after transfer switch

Have you considered an electronic 480v circuit breaker where you can exchange rating plugs, one for each currect rating?

 

[boomer3]

Re: circuit protection before or after transfer switch

Originally posted by templdl:
Have you considered an electronic 480v circuit breaker where you can exchange rating plugs, one for each currect rating?

I need to go through a transformer to step up the 240 vac feed to 480. Therefore I can't use a common feed. The secondary side of the xformer has the same amp rating as the 480 feed.
So I don't think that would help.

Thanks for the response, though...