diy solar

diy solar

Subpanel is 99% 120V except by Dryer that is 240V. Is it still okay to connect the Inverter AC-OUT 120V into both L1/L2 ?

It won't travel to the main panel.
Shortest path is correct.

And panel feeders are not in the category of a multi-wire branch circuit. Just an FYI.
Thank you sir...... this post started as a question about a 240V dryer outlet and became a really good and nice class about panels....
Thank you again....
 
And panel feeders are not in the category of a multi-wire branch circuit. Just an FYI.

But aren't they subject to the same issue, loss of neutral applies incorrect voltage to 120V load?

(Also, if you connected a really large 120V generator feeding L1 + L2 then N could be overloaded, but any reasonable generator of such size would be split phase, so not going to happen.)
 
But aren't they subject to the same issue, loss of neutral applies incorrect voltage to 120V load?
Loss of any split-phase neutral is an issue. (For 120v loads)
But it's not a code violation.
(Also, if you connected a really large 120V generator feeding L1 + L2 then N could be overloaded, but any reasonable generator of such size would be split phase, so not going to happen.)
Correct on both statements.
 
Hi @Hank Waconda , not if I understood what you said. But here is what I have today in my main panel.
View attachment 147436
View attachment 147437
It is a 240V split phase for the generator breaker with the interlock. It is to be use by a Wen GN625i.
https://generatorbible.com/generators/wen/gn625i/

So it is a invert generator and I hook up it using its 240V 30A (L14-30R) receptacle into my main panel today and it is able to run everything, except the furnace, in my house. Even the AC heat pump with a easy started it can run.
But again, the idea is to isolate the sub-panel L1/L2 wires but as you guys said the neutral will be shared, is that okay or something else to take into consideration ?

Here is my sub-panel.
View attachment 147441
And you can see it doesnt have a Top Main breaker. The idea is (if possible) move the 2 top right breakers (kitchen GFCI outlets) to the botton and add a 240v breaker for the Solar system 120v AC output but connecting both L1/L2 as that was the idea. And of course the Solar system breaker and the Top Main one MUST have a Interlock.



Thank you....
In the subpanel, only the 2 20A breakers in the bottom left could have a shared neutral. The reason is that none of the AFCI breakers above are for shared neutrals (they take 2 slots and cost a fortune, asked me why I know ;-).

To find out if those 2 breakers share a neutral, follow the wires from them to wherever they enter the panel. If they come from the same Romex cable, you're out of luck: they have s shared neutral. If not, you should be fine in this regard.
 
If they come from the same Romex cable, you're out of luck: they have s shared neutral. If not, you should be fine in this regard.

Simple solution in that case - put both hots in one breaker.
The two circuits are then limited to 20A total, but you can drive the panel single phase and not overload neutral.
 
Simple solution in that case - put both hots in one breaker.
The two circuits are then limited to 20A total, but you can drive the panel single phase and not overload neutral.
Clever! After that, adding an AFCI/GFCI combination outlet to the first outlet, if any, inside the house for each circuit would probably be enough protection.
 
AFCI/GFCI outlet could protect itself, but likely not work for daisy chained outlets because it would see only one hot leg but combined neutral currents. You can use a single pole AFCI/GFCI breaker.

Was the issue related to AFCI/GFCI? I assumed it was feeding single phase to a split-phase panel.
 
First of all, I'm super new on this solar/inverter world. So, please, easy....
Here is my scenario that Im pretty sure that a lot of people may have something similar.
  • Main panel receives 240V split phase from grip.
  • Everything in the main panel has a 2 pole breaker (240v split phase)
    • Generator 30amps breaker (it has an Interlock)
    • AC heat pump breaker
    • Furnace heater breaker
    • Sub-panel breaker
  • At the sub-panel 99% of all breakers are 120V (15amp or 20amp) EXCEPT by the Dryer that is 240V that I DONT USE AT ALL as I have a gas dryer, but the breaker/outlet everything is there just in case I (my wife) need it.
When I started to study about this solar/inverter world I came with the idea to not touch in the main panel (at least for now) and just connect the sub-panel into the solar system. So still using the grid/generator for the AC/Furnace and using another Interlock in the sub-panel to be able to totally disconnect it from the main panel and at the same time safely allowed connect it into the solar system. Or even in case of a main failure in the solar system be able go back and reconnect the sub-panel into main panel 100%.
So far so good until I start to think which would be the a good inverter to my design. First thing that came to my mind is that I would need to have a 240v split phase inverter. In my mind it is simple. 240V split phase comes from the main panel, so in order to replace it I also need a 240v split phase. So I started to research by reliable 240V inverters, like the ones from Schneider as they look to be bullet proof beasts. But then I red in this forum someone talking about have 240v split phase VS really have 240v split phase loads and as I said before, on my sub-panel 99% of the breakers/loads are single 120V phase EXECEPT by a 2 pole breaker for the dryer THAT I DONT USE AT ALL (at least now).
So we go back to the title of this post. It looks like that I could use a nice 120V single phase interver to connect into my sub-panel and have both L1 and L2 legs connected. So this way I will have 120v single phase (not 240v split phase) into both legs.
  • IS IT RIGHT ? 120v connect into both L1/L2 legs of my subpanel
  • If so how I would do with that dryer breaker ? Is it okay to leave it there ?
  • If I lease it there what happens if in the future someone goes and connect a dryer into it while the solar system is the one that is providing power to the sub-panel ? Is it safe or even legal ?
Sorry my long post but as I said... Im totally newbie and just trying to learn as much it is possible.....

Thank you everyone......
L2 must be 180 degrees off from L1. What you have suggested will not work
 
(some) dryers can be rewired to run off 120V. Apparently newer GE use 240V for controls and motor, but the ones I have didn't. That could let you do all 120V.

If you do connect L1 an L2 in parallel, and branch circuits with shared neutral and separate 20A breakers on red & black wires could but 40A through neutral, no bueno!

Examine your circuits to see if any 3 + ground cables go to two separate breakers. Or a 2-pole could have been used this way. Understand what is connected to any 3 + ground cables.
 
Just another case of responding to the first post, without realizing that there are already 46 replies.
And that it's all been hashed out, nicely.
We've all done it. lol
 
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