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Sat Apr 01, 2023 5:16 pm

I wasn’t planning on having an inverter in the van. Was initially thinking about just finding 12v chargers for most devices. I ended up deciding I might need a smaller inverter for one off circumstances, so I decided to check out Amazon. Ended up grabbing a 1000W pure sign inverter for close to the price they wanted for the smaller 200w portable units.

Have been thinking about some possible wiring set ups. Was thinking that it might be nice to just hard wire the inverter into the existing shore power outlets from a space perspective, but also thought it’d be cool to possibly “backfeed” the shore power plug to get power for certain outdoor uses.

Wouldn’t ever intend to operate inverter and plug into shore power at same time. Wondering if I would need to have something (switch etc) to actually isolate the inverter at 120v from the outlets when shore power is plugged in to avoid damaging the inverter? Obviously, I could just keep the two systems separate, but thought this configuration might have some perks. Just floating the idea to see if anyone has any thoughts or suggestions?

Thanks in advance!

Sat Apr 01, 2023 5:18 pm

Keep them separate. You can use a power strip off of the inverter to make plugging into it convenient. That is what I did. To each his own. YMMV.

Sat Apr 01, 2023 6:06 pm

Keep them separate - you can snip the connections between the upper and lower mains outlets above the shore power breaker, and have the lower outlet fed by the inverter. This is what I've done.

Also, you do NOT want to power up the shore power chassis-mounted plug on the outside...

Sat Apr 01, 2023 7:27 pm

If you want to add an inverter to your existing outlets you’ll need to wire in an automatic transfer switch or an inverter that has automatic load transfer capabilities. The inverter will need to be wired into the shore power connection between the outlet and 15A breaker.

I’ve not seen many folks on here with setups like this but I have a progressive dynamics inverter with automatic transfer switch hard wired to my outlets and it works great.

If you have any questions on how it works or the wiring send me a pm.

Sat Apr 01, 2023 8:40 pm

I have an auto transfer switch as mentioned above. Xantrex makes them. Pretty simply to wire up. It does not work with GFCI outlets.

I am using a Victron Phoenix inverter with my setup.

Sun Apr 02, 2023 8:43 am

WillRB wrote: Was thinking that it might be nice to just hard wire the inverter into the existing shore power outlets from a space perspective, but also thought it’d be cool to possibly “backfeed” the shore power plug to get power for certain outdoor uses.
You absolutely do not want to go there! This is how people get killed… or at least, a nasty shock!
Quote: Wondering if I would need to have something (switch etc) to actually isolate the inverter at 120v from the outlets when shore power is plugged in to avoid damaging the inverter?
I've done this. You need a double-pole, double-throw, 120 VAC relay, with at least 15 amp contacts. It should have at least eight terminals, like this one:Put your outlets on the two common pins of the relay. Put the inverter on the two "normally closed" contacts. Put your shore power on the two "normally open" contacts, and also on the two coil contacts.

When there's no shore power, the inverter powers your outlets. When there's shore power, the relay is energized, and shore power goes to your outlets and the inverter is cut out.

The relay is under $10 at decent electronics supply places. I used one that I salvaged from an electric furnace that was being replaced by a heat pump.

Here's one, ($3.49) but it will only do about 250 watts.

Here's a better one for $8.

I'd offer to send you one from my junk box, but I'm in transit and things are packed up.