Repurposing an HVAC disconnect into a subpanel for PV and HVAC

C

Concordtom

New User
Location
California
Occupation
PV installer
Existing 200a MSP has 60a breaker and 6AWG copper supplying a 5-ton HVAC with outside service disconnect pull-fuse.

I want to remove the disconnect box, replace with a 100a subpanel, and install 2 breakers inside: 60a breaker for HVAC (I’ll merely relocate the service disconnect box) and a new 40a PV breaker.

Does anyone see problems here?

By my reasoning: The 40a PV fits within the original 200a per the 125% rule at the MSP.
Meanwhile, within the new subpanel, the HVAC (draw from grid) and PV (supply to grid) counteract each other along that 6AWG/60a from MSP and would therefore not overwhelm.
 
The MSP's 60A breaker would need to be at the opposite end of the bus from the grid connection. With that, you are good to go, the MSP complies with the 120% rule (not 125%), and the new 100A panel complies with the "sum of sources does not exceed the busbar rating" rule, so no limit on location of the 40A PV breaker.

Cheers, Wayne
 
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