Wire output of 400w invertor to shore plug on outside smart?

MDKMDK wrote:
"You cannot safely feed the panel with the inverter with the shore power cord active but disconnected."

Where did I say I was going to do that?

"It's not legal according to code."

Um, yup. I believe I said way back that we would use the basic premise that I wasn't going to try to run more than one power source through the coach receptacles at one time.

No need to get defensive, folks are only trying to help. The point being made is that your intent on how you'd use a double wired setup is irrelevant as it's still illegal and is the reason transfer switches exist - to allow only one source at a time to feed the load. Your argument is no different than one wanting to use a suicide cord from a genset to a receptacle in order to power all the circuits in the rig ... electrically it would work but it's still illegal and ill advised. Same argument also as one wanting to feed a house breaker box with a genset without going through a transfer switch - illegal and could kill a line worker if that genset power reaches the outside lines feeding the house. Code regulations exist for a reason - to prevent people from doing what you want to do, to save lives. Your intention to have two different power sources feed the trailer's electrical input but with only one active at any given time from just one source is irrelevant - it doesn't meet code and is illegal. If you don't want to use a transfer switch then you still have two others choices - feed the trailer whole house as previously discussed OR wire in totally separate receptacles that are powered by just the inverter.

Covered this 4 posts back. The inverter I suspect will be installed in the new rig doesn't have an auto-transfer switch. They do build one that has one, but it's not the one Winnebago installs at the factory.

"You cannot safely feed the panel with the inverter with the shore power cord active but disconnected."

Where did I say I was going to do that? I didn't say anywhere in any of my prior posts that I planned on using the inverter to power the receptacles while the shore power cord was active but disconnected, either in a 30A campsite post or the generator.

"It's not legal according to code. If you forget to disconnect when turning on the inverter, the two sources would fight against each other (the mains power from the shore would win, of course). If you forgot to disconnect it from a traditional, non-inverter generator, and turned on the inverter, the generator head would act as a motor and (try to) turn the engine of the generator. If you didn't have it plugged into anything but touched the prongs, you'd get a shock or worse; and if it happened to flop against something conductive, you'd have arcing and could well start a fire."

Um, yup. I believe I said way back that we would use the basic premise that I wasn't going to try to run more than one power source through the coach receptacles at one time. I suggested this was part of a project to use the inverter and batteries to power the coach receptacles standalone, as in an off grid situation. I wouldn't be sitting anywhere near a live 30A receptacle to use shore power. No campground posts out on the USFS roads, or the BLM lands dispersed camping ares that I know of. I also wouldn't have it plugged into the generator 30A outlet. Just wouldn't happen. Sorry, if that wasn't clear.

Thanks for your comments and input.

MDKMDK wrote:
Yes, the coach's AC outlet distribution feed is what I would like to feed (when the shore power cord is unplugged from everything) from the PSW inverter, when camping off grid. I thought that was located somewhere in the converter charger area, perhaps?
Although I don't have the manuals on the inverter yet, because the unit is still being built, I thought most newer PSW inverters had circuitry in the output AC end to prevent AC current from another source flowing back into the inverter? Like diodes in a battery separator? One directional current flow from the inverter AC out? Is this not true? I also thought some of them have the equivalent of an automatic transfer switch built into the AC output circuitry for just that purpose? To sense when they aren't the only source of AC current and shut themselves off.
I believe I can manually shut off the inverter prior to plugging the 30A power cable into shore or the generator.

The AC electric panel--which is generally similar to the one in a house (or, more precisely, to a subpanel in a house)--is often located in the same physical chassis as the converter.

I don't know how inverters react to being back-fed with power, but I would not bet on most surviving such treatment. Some are designed with transfer switches built-in, but there the power input and power output would be separate connections.

You cannot safely feed the panel with the inverter with the shore power cord active but disconnected. It's not legal according to code. If you forget to disconnect when turning on the inverter, the two sources would fight against each other (the mains power from the shore would win, of course). If you forgot to disconnect it from a traditional, non-inverter generator, and turned on the inverter, the generator head would act as a motor and (try to) turn the engine of the generator. If you didn't have it plugged into anything but touched the prongs, you'd get a shock or worse; and if it happened to flop against something conductive, you'd have arcing and could well start a fire.

You must have some sort of a transfer switching arrangement between two separate sources feeding the same AC circuits. It's that simple. Directly wiring them together, even through an electric panel, doesn't allow for that. Please don't cut corners and try to do so.

I do the "whole house" thing with a GFCI receptacled inverter by plugging the shore power cable into it. The RV's GFCI circuits have no problems at all with that.

Also, I have no clue if the inverter is "floating" or not. Don't care; everything works great. My Honda gen is floating neutral and it works great too.

Only issue with all that seems to be if you have one of those Ewhatsit gismos that I don't have, when you have to use a bonded plug adapter. Easy solution is don't get one of those gismos! I do have a surge protector on the shore power cord, but that is a different animal.

Here is a 30 amp transfer switch you can add to any inverter. But use it with a inverter without a GFI if your doing the plug in method..

https://invertersrus.com/product/powermax-pmts30/?gclid=Cj0KCQjwv73VBRCdARIsAOnG8u3rDq8XnDtrhMv3y1b_PDzs7jU8JYj0cIxNZFyjCqu4MJAyjNHzt0EaAkqAEALw_wcB

Only use an inverter with GFI if its a hard wired unit...

Whats the model inverter your looking at?

If you want to do an inverter with GFI's and the plug in method they you need to run dedicated outlets like sound guy did..

Lots of options..

Good input everyone. Thanks for sharing all your experience.
It's a lot to digest but most of it seems logical, and I can follow it.

SoundGuy wrote:

MDKMDK wrote:
I'mm trying to avoid the "pita" that SoundGuy got around by adding new receptacles to his inverter, by trying to utilize the existing wiring and outlets. I understand that it's dangerous if I hit them from 2 different AC power sources simultaneously.

Here's a series of 10 pics of my inverter installation that might convince you dedicated inverter receptacles which are completely separate from the rest of the trailer's electrical system is the best solution. This avoids "hitting" any circuit with two different sources at the same time, avoids having to turn devices off if using the "whole house" method, and avoids the complication of a transfer switch which isn't immune to failure. Sometimes the best solution is the simplest solution. ;)

For those who want to use an inverter while dry camping this won't apply but for those of us who primarily use an inverter only when campsite shore power fails (which happens several times each season to us) there's another significant advantage to dedicated inverter receptacles. When power fails I just leave the trailer's main service cable plugged into the (now dead) campsite power post. In the meantime the trailer runs on battery power and inverter power BUT when campsite shore power is restored I know instantly by glancing at my EMS display as the camper automatically returns to running on shore power, including the fridge, including the water heater electric element, including the converter. It all happens automatically, no need to switch anything on or off other than the inverter which I control with the remote mounted inside the camper. Couldn't be easier or more seamless. :B

Thanks. I'll probably have to consider this option. I just checked the specs on the probable inverter make and model and it doesn't have a built in auto-transfer switch. I'm still pretty sure I could do plan A but your setup is interesting and doesn't require the transfer switch.

Two possible issues:

A. If you have a built-in generator in the RV, it will no doubt have a transfer switch with shore power. If you unplug from shore power and plug the cable into your inverter instead, and now also run the gen, can you get 240v? I don't know, but I do know it would be bad!
(With a portable gen, this is not a problem--unplug from inverter and plug into gen)

B. Many (some for sure like 7300s) have the converter on the same AC breaker as the receptacles. This means you can't use the breaker as the on/off switch for the converter, or your receptacles will all be dead too, defeating the whole idea. Now it depends on a bunch of things to do with your rig.

1.You can just unplug the converter from its receptacle if it is a plug in type, or

2. If it is "hard wired" you can snip the black wire into the breaker that comes from the converter, and insert a switch ( I used a regular household light switch) so now the converter can be switched off but the receptacles stay live with that breaker still "on", or

3. You can move that converter's black wire from the receptacles' breaker over to a different breaker you were not going to use off-grid anyway, like for the water heater, or

4. If the panel has room, you can add a breaker and make that one just for the converter, and use it as the converter's on/off switch.

Good drawing of the situation that started the thread. I'mm trying to avoid the "pita" that SoundGuy got around by adding new receptacles to his inverter, by trying to utilize the existing wiring and outlets. I understand that it's dangerous if I hit them from 2 different AC power sources simultaneously.
That's what I wanted to do.
The GFCi to GFCI thing was mentioned in a prior comment addressed to me with red text. I said I wasn't sure how that would work, but I was thinking Drew's explanation of either one or the other tripping, was the most likely result.

If you want an all automatic one instead of plugging in and out like I do, then you just need an inverter with a built in transfer switch..

You still mount the inverter near the batterys..

But now you will need to diconnect the umbilical cord where it attached to the converter. Run it to a junction box. From that junction box youll need to run 120v romex type wire to the inverter, then from the inverter back to where you disconnected the umbilical cord from the converter..

This way when you plug into pedestal your running off shore power. Then when you simply unplug it will run off inverter. Automatically. ( well your still have to push a button to turn on inverter.)

you'll need one with a 30 amp transfer switch I assume... Youll be paying a pretty penny for this type of inverter for sure..

My install was less than $150 bucks.

MDKMDK wrote:
I'mm trying to avoid the "pita" that SoundGuy got around by adding new receptacles to his inverter, by trying to utilize the existing wiring and outlets. I understand that it's dangerous if I hit them from 2 different AC power sources simultaneously.

Here's a series of 10 pics of my inverter installation that might convince you dedicated inverter receptacles which are completely separate from the rest of the trailer's electrical system is the best solution. This avoids "hitting" any circuit with two different sources at the same time, avoids having to turn devices off if using the "whole house" method, and avoids the complication of a transfer switch which isn't immune to failure. Sometimes the best solution is the simplest solution. ;)

For those who want to use an inverter while dry camping this won't apply but for those of us who primarily use an inverter only when campsite shore power fails (which happens several times each season to us) there's another significant advantage to dedicated inverter receptacles. When power fails I just leave the trailer's main service cable plugged into the (now dead) campsite power post. In the meantime the trailer runs on battery power and inverter power BUT when campsite shore power is restored I know instantly by glancing at my EMS display as the camper automatically returns to running on shore power, including the fridge, including the water heater electric element, including the converter. It all happens automatically, no need to switch anything on or off other than the inverter which I control with the remote mounted inside the camper. Couldn't be easier or more seamless. :B