120 VAC electric panel modification

[chin_k]

I think I need to wire the ATS *after* the breaker for this to work, but that means I will need to add a separate 15A breaker to make sure the circuit is not overloaded.

Let me know if I am mistaken, but if I put the ATS between the breaker and the shore/gen set source (that is, before the breaker), it won't work because the current from the inverter will energize the charger, since they share the same bus, which is what I try to avoid.

[caconcourse]

I think I need to wire the ATS *after* the breaker for this to work, but that means I will need to add a separate 15A breaker to make sure the circuit is not overloaded.

Let me know if I am mistaken, but if I put the ATS between the breaker and the shore/gen set source (that is, before the breaker), it won't work because the current from the inverter will energize the charger, since they share the same bus, which is what I try to avoid.

I believe that black wire at the bottom is actually "after the breaker", as it is the external wire that leads to the outlets. The power to the breaker is the bus that it snaps into. There is also the GFI protection in the first outlet that will protect the circuit from a short.

[chin_k]

Sounds like it is a doable mod in that case then. I think I still want to have a breaker after the add-on ATS just for safety. I am going to get a new inverter to replace my current one, but the existing one can do 20A for a short period, so it will not be safe if there is any short in the wiring after the ATS (I don't think the ATS can self-destruct if 20A go thru it, does it?)

[chin_k]

After talking to someone who have more experience with RV electrical, this setup diagram was pointed out to me. So it is identical to what you described, Clay, but the main difference is the following:

1, a separate sub panel for housing the breaker(s) that will be powered by the ATS/inverter.
2, all circuits will have a disconnect after the ATS

For my rig, there is only one breaker than need to be powered by the inverter, so it will be simpler if the subpanel is eliminated, but that is not a good idea due to safety reason (possibly RVIA or electrical code violation). I was told a breaker before the ATS is not sufficient, even if there is only one circuit.

The question now is, is there any place where I can put the subpanel?

[caconcourse]

After talking to someone who have more experience with RV electrical, this setup diagram was pointed out to me. So it is identical to what you described, Clay, but the main difference is the following:

1, a separate sub panel for housing the breaker(s) that will be powered by the ATS/inverter.
2, all circuits will have a disconnect after the ATS

For my rig, there is only one breaker than need to be powered by the inverter, so it will be simpler if the subpanel is eliminated, but that is not a good idea due to safety reason (possibly RVIA or electrical code violation). I was told a breaker before the ATS is not sufficient, even if there is only one circuit.

The question now is, is there any place where I can put the subpanel?

Since the first outlet on the circuit is a GFCI protected outlet, I would ask the electrician if that would be acceptable instead of a subpanel/breaker for protecting the outlets when using the inverter. The GFCI is in effect a breaker.

[caconcourse]

Or maybe you can go with a simple inline 15A breaker (or 20A version) like this:

https://www.amazon.com/dp/B07FS6PFW4/re ... a69bc8a492

with a manual reset. I assume the inverter has an on/off switch if you want to remove inverter power form the outlets altogether.

[chin_k]

GFCI can be function as a switch, (when you press the "TEST" button), but it is not a substitute for a circuit breaker. It is for protection from situation where current that does not return from the neutral line (something like around 250 mA???), not for overloading of circuit. They serve a completely different purpose. For some newer houses, they have GFCI, AFCI, and circuit breaker. Each serve a different purpose, and none of them can replace any of the other two.

[Edit] I think for safety, I will look into getting a subpanel somewhere installed by the main panel before I do any modification to the existing one.