Minimum residential Main Panel Amperage rating for a residential house in California for a photovoltaic system

[MexiCanSparky]

Having a dispute or trying to locate in NEC the minimum electrical panel size to supply or feed a new photovoltaic system on my house in California. I think I got bad information that it was required to be 200amp VAC minimum for Main Panel
Service to house but I know feeder or line side of photovoltaic system doesn’t need to be that big unless for some reason calculations dictate so.. Asking so I can educate myself and make sure I’m not being scammed. Solar company did an assessment prior saying I need a new panel but now trying to say it’s fine on my old Zinsco panel. Which I been doing research that are fire hazard n recommend replacing.

 

[Dennis Alwon]

I am not aware of any minimum size for the service panel other than 100 amps for a residential service.

If your panel is rated 100 amps then the most solar you can get is 20 amps which isn't very much

 

[ggunn]

I am not aware of any minimum size for the service panel other than 100 amps for a residential service.

If your panel is rated 100 amps then the most solar you can get is 20 amps which isn't very much

Load side, of course, and that is 125% of the max inverter output, so 16A of inverter output; as you say, that's not much. On the line side one can connect up to 100A (80A of inverter output).

The NEC does not require a minimum service size to interconnect a PV system, but the AHJ very well might.

 

[mtnelect]

This is from the City of Los Angeles "Simplified Submittal" online. See page 3, showing 100-to-225-amp services.

 

[mtnelect]

This is a better copy.

 

[jaggedben]

Having a dispute or trying to locate in NEC the minimum electrical panel size to supply or feed a new photovoltaic system on my house in California. I think I got bad information that it was required to be 200amp VAC minimum for Main Panel
Service to house but I know feeder or line side of photovoltaic system doesn’t need to be that big unless for some reason calculations dictate so.. Asking so I can educate myself and make sure I’m not being scammed. Solar company did an assessment prior saying I need a new panel but now trying to say it’s fine on my old Zinsco panel. Which I been doing research that are fire hazard n recommend replacing.

There is no rule in the code that sets a minimum specific to solar, although for any given existing service there will usually be a number of details that constrain the size of solar system you can install, given which of various rules apply. And thus the answer real answer is: it depends. See article 705.

I've run into a couple jurisdictions that won't issue a permit if you have a Zinsco panel, unless the permit includes replacing it. Only a couple. But not a bad idea to replace Zinsco, in general. At which point not necessarily worth pinching pennies to install less than 200A.

 

[jaggedben]

If your panel is rated 100 amps then the most solar you can get is 20 amps which isn't very much

That's incorrect if it's possible to do a supply side connection or in some other scenarios. The limit could be up to 80A inverter output, depending on details.

 

[ggunn]

That's incorrect if it's possible to do a supply side connection or in some other scenarios. The limit could be up to 80A inverter output, depending on details.

As I said in post #3.

 

[Zee]

No minimum size.
Zinsco bad.
If you replace it as part of your PV project, you save 30%.
That can be huge.

 

[GoldDigger]

I am not aware of any minimum size for the service panel other than 100 amps for a residential service.

If your panel is rated 100 amps then the most solar you can get is 20 amps which isn't very much

But keep in mind that a nominal 100A panel may well contain a bus rated at 125A, which would give you an extra 25A to work with.
Depends on how you interpret "rated."