[RE-wrenches] down-sizing main breaker
William Miller
william at millersolar.com
Sun Aug 2 14:09:20 PDT 2009
Dick:
Regardless, the code requires that all portions of the circuit accommodate
the sum of the over current devices supplying the circuit. The citation is
below.
I am not defending the code, I am telling you what I believe it says. You
don't need to sell your view point to me, you need to sell it your local
building officials. My goal is to interpret the code such that my designs
are unassailable by building officials. I don't want unpleasant surprises
after I have signed a contract and begun work for a fixed price.
690.64(B)(2) The sum of the ampere ratings of overcurrent devices in
circuits supplying power to a busbar or conductor shall not exceed the
rating of the busbar or conductor. (2002).
William Miller
At 01:15 PM 8/2/2009, you wrote:
>Wlliam,
>
>If there were to be a short circuit in the feeder or the main service panel (
>the one with no extra breaker spaces ), the solar's maximum 50 amp
>contribution
>would be about the last thing to be concerned about. A short is going to
>result
>in perhaps 1000s of amps coming from the grid into the short. The service 100
>amp breaker will trip immediately and clear the fault. The inverter will lose
>the grid and drop offline. End of story.
>
>Dick
>
>--- You wrote:
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