There are two breaker spots in the 125A panel. (we have been calling this a 'disconnect main panel')
One breaker spot is a 90A feeding the house sub. The other breaker spot has a 40/20 quad. (40 for AC)
We planned on putting a 40/40 quad, relocating the 20, and 30A of solar to a new sub.
But the AHJ is saying that you cannot have more than 125A of breakers. (combined total)
So per their rule, the existing is already over the panel capacity??
I would love to be able to explain to them and correct their thinking if they are wrong about this.
So I see a couple things I see going on here...
First issue is that before you guys arrived on the scene the panel is already potentially out of compliance. There's 160A of load breakers on the 125A panel. That's not
necessarily a violation. Find your codebook and read that 230.90 Exception 3 that I mentioned above. That is pretty key. You've got to do a load calculation on this house and show the plan checker that the calculated load is under 125A. (Note: the solar is not a load.) If it isn't under 125A, well, that's the customer's problem...
Second potential issue ... I'm not sure from what you've said if the plan checker is just concerned about the first issue or if he's also got a wacky interpretation of 705. In the meter main, you're doing a supply side connection under 705.12(A). Well, in this case you have a load side connection in series with a supply side connection, but none of the 705.12(D) rules apply to the meter/main busbar because it is not on the load side of the service disconnecting means. If the quad wasn't blocking you, you could put a 125A solar breaker in that second spot as a supply side connection. Perhaps he's looking at 705.12(D)(2)(3)(c), but I just think that is wrong because the beginning of (D) refers to load side connections and so, to repeat, that section doesn't apply to a busbar on the supply side of the service disconnecting means. I have done a
lot of interconnections on these types of panels under this logic.
If you can get on the right side of this guy you'll save yourself a good deal of trouble in Oakley where I'd guess a sizable percentage of houses have a meter/main with two breakers, one for a sub and another for the A/C.