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I'm applying for my PV permit in San Diego (power company is SDG&E), and on step 10 of the template it asks about "Point of Connection to Utility". I'm not sure which my plan falls under. I'm attempting to use the line diagram attached. Am I a "Supply Side Connection" or "Load Side Connection"?

This is roughly the order of devices I was planning on using

Aptos Solar DNA-120-BF26-370W Bifacial Solar Panel --> Enphase IQ8M-72-2-US IQ Microinverter --> IQ Combiner 4 --> Enphase EP200G-NA-02-RSD Rapid Shutdown Switch --> 200A Service Panel --> Meter

Point of Connection to Utility

Permit Question

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  • 1
    How are you connecting the circuit from the inverter to the panel? A branch breaker, or some other way? Feb 21, 2023 at 3:52
  • @ThreePhaseEel I planned on using the IQ Combiner 4 to collect the 3 strings from the roof. Then I planned on connecting the wiring coming out of the IQ Combiner 4 to the house electrical panel. Feb 21, 2023 at 15:13

1 Answer 1

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"Load-side" and "supply-side" refer to the perspective of an observer "standing" at your main disconnect (the 200A breaker in your main panel). "Supply" is the side the utility is on; "load" is the side all of your branch circuits attach to. Based on your description "Rapid Shutdown Switch --> 200A Service Panel --> Meter," your connection is load-side.

Because yours is load side they ask precisely where the PV circuit breaker will be installed in relation to the main breaker. If the main breaker is at one end of the breaker bus (ie top or bottom), and the PV circuit breaker is at the extreme opposite end, you get to use the 120% limit. Otherwise use the 100% limit. Some panels are center-fed: the main breaker sits in the middle with bus bar going both up and down. I believe this arrangement is subject to the 100% limit.

By way of information, a supply-side connection would look like a tee. The PV connection is parallel to, rather than downstream of, the main breaker. "PV connection" in my diagram below incorporates a panel of some sort, a circuit breaker, provision for rapid shutdown, etc.

Utility service drop---|
                       |
                     Meter
               ________|_______
              |                |
        PV connection     Main breaker
              |                |
           inverter       branch circuits
           combiner
           PV panels, etc

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