[RE-wrenches] line-side tap in subpanel

[Erika M. Weliczko]

Greetings all,

When the subpanel is fed with 380A wire and the OCD is 400A and the panel
bus is 400A, which number would be used for determining 120% capacity?

I'm thinking the 400A because the bus would be overfed before the wire?

So if we want to land 225A of OCD for solar output on the line terminals or
a backfed breaker, we need to derate existing OCD to subpanel all the way to
255A, or realisitically 250A if the load calcs allow it.

Or replace the feeders serving the subpanel. Yeah, right.

 

While for this one it does not end up mattering, it raises the question.

 

Thanks for input,

Erika

 

 

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