running 120v invertor plugs off a generator

[trophylite]

Hope this makes sense !! Coming off the invertor, there are four plugs in various locations to power the rear & front tv and two other plugs in various locations.. My question is, I want to backfeed one of the plugs (which will energize the other three) from a portable 1000w honda generator to watch tv without draining the batteries.. My question is, being the wiring of these four plugs goes back into the invertor, could damage be caused to the invertor being voltage is being applied INTO the invertor from reverse order or is there a diode that prevents damage if voltage is applied backwards into the invertor.. May need to contact the invertor mfg., but just thought someone has tried this before.. When dry camping we use the tv's alot and seem to drain the batteries due to the fact I would rather not run the big generator all the time...Thanks

[Ernie n Tara]

I'd contact the manufacturer, but this doesn't sound like a great idea unless you can get to the wire feeding those plugs form the inverter and install a switch or, better yet, a NC relay that is activated by the socket you put the external generator output to (so it disconnects the inverter on sensing the power). Note that this may well exist already if you have provision for an external AC input, but then you would not have asked the question?
Ernie

[trophylite]

Originally Posted by Ernie n Tara

I'd contact the manufacturer, but this doesn't sound like a great idea unless you can get to the wire feeding those plugs form the inverter and install a switch or, better yet, a NC relay that is activated by the socket you put the external generator output to (so it disconnects the inverter on sensing the power). Note that this may well exist already if you have provision for an external AC input, but then you would not have asked the question?
Ernie

Yea that's what I was thinking...Would be so much easier if I could just plug it into the shore power, but it tries to energize the invertor, refer, and alot of other charging accessories that overload that little 1000w Honda..All i want to do is energize the 4 plugs.. Maybe someone else on here knows something about how the invertor works...Thanks for your info

[Good man]

trophylite,
You pose an interesting question ...and it is very sensibly stated.
Agreed, it is more sensible to utilize the smaller, quieter, more efficiently rated portable generator to power the TVs.
...And, your rationale for wanting to "backfeed" is arguably defensible up to a point. That point is "convenience" ... and it is always trumped by "SAFETY".
It is NEVER a good idea to 'backfeed" any circuit. The "live" end of the backfeed cord itself is a hazard. Add to that, you now have an inverter in play in the RV aalication.
You are wise to ask "what will happen?" I haven't a clue.

I DO know that when "backfeed" voltage goes upline and hits a stepdown power transformer, the reverse happens and the backfeed voltage is STEPPED-UP ...and can go for great distances in the utility power grid.
That is why linemen will not touch their utility lines in a storm restoration operation if they hear a generator running.

As to the theoretical question you pose regarding the inverter...
One of the members of iRV2 uses as his "motto" the following:

"In theory, there is no difference between theory and practice, but in practice, there is." Graham Gracie

Bear in mind that you may get a lot of answers... most of them will be "theroetical" and there are many variables, i.e.;
...what if you forget to unplug your "jerry-rigged" backfeed patch cord and tie in to shore power?... Now, you have 110 going into your generator control backwards. Even if it is not runnng, no good can come of that. If it IS running ...it won't be pretty.

Yes, I know... YOU would never, ever do that. BUT...

May I humbly suggest that for the sake of SAFETY, and to be sure that no one else ever gets hurt ...you simply use a properly rated extension cord ...or perhaps get fancy and install a line orginating at the locaton of the portable generator and terminating at a set of "dedicated" outlets at each TV location.

You are going to have to set-up and crank the portable generator anyway, so plugging in a 110 extension cord OR dedicated line is a very small concession for the sake of SAFETY.
Thanks for considering this,
Jim

[trophylite]

Jim, Thanks for the good info and I fully agree with you on the aspect of safety... I am a high voltage lineman for SCE and it sounds like you are either a lineman also or have extensive electrical theory background.. I would love to just have some dedicated plugs coming from the 1000, but would be a major job fishing new wire up walls, etc. and would have to tear half the coach apart.. Just trying to fiqure out an easy way to do it... I may give the invertor mfg. a call and see if there is possibly a fail safe remedy inside the invertor... I will post if I find something out...Thanks

[Good man]

Originally Posted by trophylite

Jim, Thanks for the good info and I fully agree with you on the aspect of safety... I am a high voltage lineman for SCE and it sounds like you are either a lineman also or have extensive electrical theory background.. I would love to just have some dedicated plugs coming from the 1000, but would be a major job fishing new wire up walls, etc. and would have to tear half the coach apart.. Just trying to fiqure out an easy way to do it... I may give the invertor mfg. a call and see if there is possibly a fail safe remedy inside the invertor... I will post if I find something out...Thanks

trophylite,
Man I gotta tell you that I feel 100% better knowing that you are a lineman! Sorry if I was "preaching to the choir"... but one never knows the level of awareness/knowledge/skills at hand with the OP.
You will find a good and SAFE way to do this, I am sure.
It's all good (...It's even BETTER, now!),
Jim

[DP01]

This may seem like a stupid suggestion.

Would you not be better served by simply connecting the Honda generator to the shore power plug using a 30A-15A or 50A -15A dogbone? Turn the inverter off and the entire RV AC system will be fed from the Honda. No backfeeding - no problems

Dennis

[BryanL]

It is NEVER a good idea to 'backfeed" any circuit. The "live" end of the backfeed cord itself is a hazard.

Ditto!

What you can often do is to use the circuit breakers to isolate selected circuits. Make it so the selected outlets are on their own separate circuit breakers. When you want to feed those, and only those, shut off all the other circuit breakers when you run off the genset.

[Big Bear Local]

Originally Posted by BryanL

Ditto!

What you can often do is to use the circuit breakers to isolate selected circuits. Make it so the selected outlets are on their own separate circuit breakers. When you want to feed those, and only those, shut off all the other circuit breakers when you run off the genset.

That's what I was thinking. Seems alot easier.

[wa8yxm]

NEVER, EVER NEVER backfeed a outlet NEVER, This is very dangerous.. I do however have a very simple option you might find interesting.

Where the 120 vac line comes out of the generator, Cut the wire, add a plug (Twist lock type is best here) and matching outlet.. The outlet goes to the Inverter, the plug to the down-line outlets.

Now, feed the plug, using the proper cord, off the generator.. No danger.

[tquarles]

Well, since most inverters if not turned on to invert just pass their input to the outputs, in your case, they'd pass the outputs back to the inputs, backfeeding your entire electrical system with the effects of:
1: tripping out your generator just as if you'd plugged the shore power cord into it.
2: Making the plug on the end of your shore power cord LIVE in the time before the generator shuts off.

I wouldn't want either of these things to happen. If you happened to plug into shore power (or did this during a blackout) you could be backfeeding to the utility lines and frying a lineman.....

I'd go for turning off most of the breakers and plugging the shore power cord into the generator. It should do what you want without the bad side effects.

[Rich and Cork]

Not sure why you don't just plug your shore power plug into the Honda?

I have a Honda 1000 also, but my present motorhome draws too much and it will kick off the Honda. So, if that is also your problem, use the 12v connector that came with the generator and connect to your batteries and just use the inverter off the batteries. My previous motorhome (a Winnebago) would run fine on the Honda using the shore power plug.

Good luck and have fun.

[PlayItForwrd]

I have to echo the 'plug it into the shorepower input" crowd. Virtually everything you DON'T want powered can be turned off, either at the unit itself or at the breaker box.

Make sure you switch the fridge from "auto" (or "elec") to "gas", the fridge alone will eat half your generator's output...

[Ed-Sommers]

Plug in a regular battery charger to the Honda and run off the battery/inverter This way you get TV and a full battery! A real battery charger is better than the Honda 12 volt hookup because a charger requires fewer RPM's from the Honda. Ed