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[malo3s]

I have three strings (AC) going into a main panel, the engineer used three disconnects and has three DP breakers, I said, you need a load center and one AC disconnect and one (1) breaker going into the main panel. Am I right?

 

[jaggedben]

No, you're wrong, unless the AC disconnect is a utility requirement or a local requirement. It is not a National or California Electric Code requirement.

 

[augie47]

jaggedben, I was waiting on someone more familiar with Solar systems to answer the OP. I would have thought otherwise due to the singular word "breaker" in 690.64(B)(1) {'08}.
Can you clarify the section for me.

 

[jaggedben]

If he has 3 AC circuits then those are three separate sources as far as I'm concerned. It obviously makes no sense to read that section as requiring that different inverters all be landed on the same OCPD. And the code does not prohibit multiple sources from being landed in a panel with loads.

Actually, there's one other thing: If an AHJ enforces 705.22(6) then you need to have a lockable disconnect, which might preclude using only breakers in the main panel, depending on details and interpretation. I often forget about that section because my AHJs don't typically enforce it and as long as there can be LOTO I consider the purpose fulfilled.

In any case under 705.22(6) there is more than one way to do it besides the way that the OP stated.

 

[GoldDigger]

Have you ever had a problem with an inspector arguing that if you have more than two back fed breakers they cannot all be at the opposite end from the main?

 

[jaggedben]

Have you ever had a problem with an inspector arguing that if you have more than two back fed breakers they cannot all be at the opposite end from the main?

No, that has never happened to me. But then I don't think I've ever done more than two in this type of situation.

Also, with two quad breakers on each side of the panel you could have up to 4 circuits all connected at the opposite end.:happyyes:

 

[shortcircuit2]

I have three strings (AC) going into a main panel, the engineer used three disconnects and has three DP breakers, I said, you need a load center and one AC disconnect and one (1) breaker going into the main panel. Am I right?

Under the 2014 NEC, this system would need to land at dedicated circuit breaker or fusible disconnecting means. Language was added in 705.12(D)(1) that clearly states that the output of one or more inverters in one system shall be made at a dedicated circuit breaker or fusible disconnecting means.

 

[jaggedben]

Under the 2014 NEC, this system would need to land at dedicated circuit breaker or fusible disconnecting means. Language was added in 705.12(D)(1) that clearly states that the output of one or more inverters in one system shall be made at a dedicated circuit breaker or fusible disconnecting means.

Still unclear what 'one system' means.