Connect Inverter to A Sub panel ???

Merry Christmas

Mhnholt

Member
Location
Union City
Occupation
Electricial engineering
I have a need to move the output of my solar inverter from the main panel to a sub panel that I need to add to my house.
I understand the calculations and understand the therory of connecting the output of a solar inverter to the grid.

What I dont know is there Anybody (The local City, the power company (PG&E), the solar police, or Oscar the grouch) would not like it, prevent it, fine me for doing this, or whatever.

Thanks
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
It is allowed as long as the rules in Article 705 are followed. (Also, why not just move other circuits to the subpanel?)

We are not supposed to help people with DIY work here. I hope that you are hiring an electrical contractor for this.

The local city may fine you if the work is done without a permit and they find out.
 

Mhnholt

Member
Location
Union City
Occupation
Electricial engineering
Thanks for the reply.
I guess that I need to explain just what I am doing.

What I have:

1. 4 aught al feed from street.
2 Challenger main with:
A) 100 amp 2 pole to a full sub panel
B) 30 amp 2 pole to 5KW solar inverter.
No positions left for breakers
3. Challenger sub panel that is full

What happened:

1. 4:00 am a few months ago discovered one pole of the breaker for the sub panel completely burned out.
2. Replaced 2 pole breaker. Working OK for now.

My loads:

240 volt loads:
1. 3 ton AC
2. Electric range
3. Electric clothes dryer

120 volt loads:
1. Just the ordinary loads used in typical home. Entertainment system, Computers, Microwave oven, fridgerator, etc.

My goal:

Split the load (which is the entire house) that exists for the one sub panel into two sub panels served by two 2 pole breakers.
The second sub panel have the AC compressor (30 amp circuit) and the solar inverter output (30 amps) plus maybe a couple of 20 amp circuits that I plan for the computer.
To do this I will have to steal the position in the main that is currently used for the solar inverter output and use this position for my second sub panel. I will then re run the solar inverter to the new sub panel.

Why I am doing this:

Even though a breaker that is rated at 100 amps, that does not mean it can supply 99.999999 amps of current for EXTENDED lengths of time.

In electronics, when sizing anything, the value of at least 20% derating should always be used. In the case of a 100 amp circuit, no more than 80 amps for any extended amount of time should be expected.


I will feel much safer having the house split up into two sub panels.

Does this make sense???
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
Broadly speaking, yes it makes sense. I'm a little surprised your A/C was connected to the subpanel and not the additional space in the main panel. I often find houses wired the second way. The solution you propose is what I usually would do if the A/C were already in that spot when I came to add the solar: add a subpanel which will have the solar and the relocated A/C.
 
Top