POI on multisource switchgear

[electrofelon]

If you say so, but that doesn't seem right to me.

you are welcome to find me a code reference, I'll wait (but only a few minutes cuz it's going to take you a LONG time to find ). Think about it, many/most switchboards have vertical sections that have a lower ampacity than the horizontal bussing and the main OCPD.

 

[electrofelon]

..... actually I might stand partially corrected. Doesn't 705 apply to switchboards in the 2020? In the 2017 the bus bar rules were only for panel boards, which some people found odd, but really it harmonizes with there being no general rule to protect bus bars in switchboards at their rating by OCPD. But didn't they eliminate the word "panel board" in the 2020? So this is strange because you still have no general rule to protect the bus bar, but you do if you have multiple sources

 

[pv_n00b]

You don't say what the PV rating is but if it's more than 1,600A there is no way to make this NEC compliant since you have no control over how the back feed splits between the three service CBs and each will have a 1,600A maximum.
As for 705.12(B)(3)(1), most rely on 705.12(B)(3)(5) to do the interconnection under engineering supervision in C&I work.

 

[pv_n00b]

I don't believe there is any requirement to protect the bus at its rating by an OCPD for a switchboard or switch gear.

It is kind of implied in the code. 230.80 requires that the combined total of the disconnects be equal to or greater than the calculated load and the SWBD bus rating has to be equal to or greater than the calculated load. It tends to work out that in a correctly designed system the disconnects end up rated to protect the SWBD bus, even though that is not an explicitly stated requirement.

 

[PeterW]

But the OP said it was 6000A

Sorry I drew this kind of hastily it is a 6,000A bus bar. not 3,500A.