I really want to wire my inverter AC output into my RV distribution panel. I have all of the wires run where they need to be. My Idea is to be able to flip the main breaker for shore power to "Off" and then flip another breaker to "On" therefore switching from shore power to inverter power. I am running into a problem where I have a hot wire coming out of the male plug at my inverter. So, I tried to isolate both hot wires with a breaker switch.... only to find out the ground wire is providing the power. I've double checked everything! It has power even when every breaker on my panel is OFF. So confused. Do I have a faulty ground somewhere???? I don't show any voltage on the ground bar or continuity between wires. Is the 3 prong plug I used connected with the ground to the neutral?

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    I'm no expert, so just a comment, but based on plenty of questions regarding generators for regular buildings, I am fairly certain you need an interlock to prevent accidentally having both shore & inverter on at the same time - which could cause all kinds of problems, including killing someone working on the shore side (i.e., utility pole) if there is a power outage so you're running on inverter and forget to turn off shore (since it's off anyway) - some serious problems can result. – manassehkatz-Moving 2 Codidact Sep 24 '19 at 2:37
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    Can you post photos of your RV's electrical panel? – ThreePhaseEel Sep 24 '19 at 3:00

No. You can't wigger-jigger it like that. I've been saying this a lot today, but if one thing is broken and wrong, it's best to fix that first - the other problem may take care of itself if you do.

You need a proper interlock so that it is physically impossible for any of the prongs on any plugs to get "lit up".

If your breaker panel lends itself to interlocks

You're on the right track with breakers where only one is on at once, but you must have physical interlock to make "both on at once" impossible.

Some models of breaker panel have very simple, inexpensive options for interlocks. Such as Square D "QO" and Siemens/Murray. (Keep in mind you must not mix-and-match breakers and panels; use only breakers listed or classified for that panel).

If this is not feasible, there's another way.

Use a plug/socket as an "interlock"

Presumably your RV has either an inlet, or a short cord-and-plug, which you plug your extension cord into in order to reach shore power.

OK, so you build a virtual "extension cord" from your inverter to that inlet/plug. On shore power, you plug the RV into shore power. On generator, you plug the RV into the inverter instead. That's pretty simple, isn't it?

The trick is, you build this "extension cord" right into the RV, using in-wall wiring methods. One end is a plug-and-cord going into the inverter, obviously. The other end depends.

  • If the RV has an inlet, then you have a cord-and-socket which is just long enough to plug into the inlet (and too short to worry about it dragging on the ground).
  • If the RV has a short cord, then you have an outlet within reach of it.

Either one simply goes straight to the inverter.

Now the procedure is simple: whenever you unhook from shore power, you connect that cord so you are looping over to the inverter.

Use 240V, 4-wire connections

I hear you saying you're using a 3-prong connector with a ground. That doesn't make any sense unless the RV is very small and uses a TT30 connector. I expect your RV is 120/240V split, and needs 2 hots, a neutral, and a ground. I suspect you have inadvertently connected neutral or ground to a hot wire, and that's why it is lit up.

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