Hi all. New member here about to pickup a Grand Design this weekend and I'm already planning out upgrades to make the rig 100% usable off grid.I'm versed in electrical but the whole inverter/charger thing is new to me and I have concerns with the split phase nature of them.Can someone correct me if I'm wrong, but if you run one leg of the 50A service to the inverter and the second leg directly to the panel, when the inverter is running wouldn't you be backfeeding the second leg.Seems that unless you kick off the breaker to that leg your shore power connection will be hot. My old Lance 5th wheel only has a male connection so that would be a major concern.Any input your have is appreciated. Thanks.

Hi Jamey,Welcome to the forums.Often there is a transfer switch, so the 50 amp-shore power cord would not be live.Mine is old school--I simply plug the shore power cord into an outlet powered by the inverter.

pianotuna wrote:I simply plug the shore power cord into an outlet powered by the inverter.HUH??:h

JaimeTheLimey wrote:Hi all. New member here about to pickup a Grand Design this weekend and I'm already planning out upgrades to make the rig 100% usable off grid.I'm versed in electrical but the whole inverter/charger thing is new to me and I have concerns with the split phase nature of them.Can someone correct me if I'm wrong, but if you run one leg of the 50A service to the inverter and the second leg directly to the panel, when the inverter is running wouldn't you be backfeeding the second leg.Seems that unless you kick off the breaker to that leg your shore power connection will be hot. My old Lance 5th wheel only has a male connection so that would be a major concern.Any input your have is appreciated. Thanks.No back feed. It all depends on how the inverter is wired. Inverter can power just circuit hooked to it OR it can go back to a split buss panel and feed just a few things in 1/2 of the panel.I think the newer high end all electric coaches it can feed the whole panel but I have no first hand knowledge on that.

JaimeTheLimey wrote: if you run one leg of the 50A service to the inverter and the second leg directly to the panel, when the inverter is running wouldn't you be backfeeding the second leg.I can't answer, but I can suggest you get a '50a' inverter.

One hundred percent off grid useable requires a generator for A/C. When A/C isn’t needed, an adequate solar system will run everything else and is preferable IMO. Do you have any plans re solar?

Question on inverter/charger AC backfeed | Good Sam Community

Veebyes
Explorer II
Feb 18, 2020
MrWizard wrote:
No need for open leg
Use a 50 > 30 > 20 adapter's
Plug into the inverter If the inverter is the hard wired type
Wire with short cord to a 30a or 50a adapter
Using an outlet and plugging in shore cord is foolproof
You can NEVER be cross connected for a dangerous n situation

Another way to do it. There are always multiple ways around a problem. No matter what though turn the circuit breakers off to the converter, water heater & fridge. Battery bank killers.
MrWizard
Moderator
Feb 17, 2020
No need for open leg
Use a 50 > 30 > 20 adapter's
Plug into the inverter If the inverter is the hard wired type
Wire with short cord to a 30a or 50a adapter
Using an outlet and plugging in shore cord is foolproof
You can NEVER be cross connected for a dangerous n situation
Veebyes
Explorer II
Feb 17, 2020
I am not a tech but have had some inverter experience on the water & on land.

Backfeeding is not good. It involves a loud bang & smoke as the inverter is destroyed.

These days I like doing things manually. I have a 1500w pure sine wave inverter going to the automatic transfer switch & a converter/charger.

Part of the drill for dry camping is to turn the breaker powering the converter/charger off, along with the water heater, microwave & fridge breakers. For shore power the inverter is turned off, i.e. not in the automatic mode.
librty02
Explorer
Feb 17, 2020
larry cad wrote:
theoldwizard1 wrote:
pianotuna wrote:
Hi Larry,

My inverter powers a 30 amp female plug. I plug the shore power cord into that inverter powered outlet.

Best non-automatic transfer switch you can have ! Simple and not too expensive.

Had to think about it for a minute, but now I understand exactly that.

This is fairly common just plug the shore power cord into an inverter. You just have to watch how many watts you pull at a time not to overload the inverter...and drain your batteries quickly...the biggest thing is turning off the breaker for the converter in the rig. With the breaker on you would be using your batteries to charge your batteries and that will drain them very quickly...it would be a never ending cycle ha!
2oldman
Explorer II
Jan 30, 2020
pianotuna wrote:
Are you saying you wish to run the RV as an uninterruptible power supply?
Just the DTV. My MW clock will stay on time if I make the manual switch fast enough.

My old Prosine 2.0 had a fast enough switch to keep the older DTV SD receiver on, but the HD ones are really sensitive.
pianotuna
Nomad III
Jan 30, 2020
2oldman,

Are you saying you wish to run the RV as an uninterruptible power supply?

In fact, because I do have an inverter/charger that does load support, that is how my unit could be run.

It also means that if running on the generator, and fuel is needed I can continue powering the RV.

I use a patch panel approach for those times when shore power "hates" the Magnum (gfci some don't like Magnum).

My apologies as this is off the topic which is back feeding--which any thinking person would agree is a lousy and dangerous practice.
2oldman
Explorer II
Jan 30, 2020
theoldwizard1 wrote:
Best non-automatic transfer switch you can have
Unless you have sensitive equipment like a DTV receiver which will shut down and take 7 minutes to reboot in the middle of recording your favorite show.

I use a 3pdt manual knife switch, but, my receiver is hard-wired to my inverter which is never off.
larry_cad
Explorer II
Jan 30, 2020
theoldwizard1 wrote:
pianotuna wrote:
Hi Larry,

My inverter powers a 30 amp female plug. I plug the shore power cord into that inverter powered outlet.

Best non-automatic transfer switch you can have ! Simple and not too expensive.

Had to think about it for a minute, but now I understand exactly that.
theoldwizard1
Explorer II
Jan 30, 2020
pianotuna wrote:
Hi Larry,

My inverter powers a 30 amp female plug. I plug the shore power cord into that inverter powered outlet.

Best non-automatic transfer switch you can have ! Simple and not too expensive.
larry_cad
Explorer II
Jan 30, 2020
pianotuna wrote:
Hi Larry,

My inverter powers a 30 amp female plug. I plug the shore power cord into that inverter powered outlet.

larry cad wrote:
pianotuna wrote:
I simply plug the shore power cord into an outlet powered by the inverter.

HUH??

:h

Interesting concept. I've never seen that done.