Back feeding power to sticks and bricks from generator

[charlie2]

We had a power outage at our house the other day and hooked our garage refrigerator to the outside outlet on the motor home while running off 7500 watt Onan diesel generator. worked fine. Talking to a licensed electrician after words and he said I could have cut the main power feed to the house from consumers power company, plugged the motor-home to the RV outlet I have on the house and it would have back-fed the entire house. Doesn't sound right to me. Is he correct?

[Frutza]

No your automatic transfer switch wont allow it, you can rewire to use it in an emergency, but you better know what your doing

[bdickson]

He gave you incorrect and possibly dangerous advice. The 50 (or 30) amp cable on the MH is one input to the Transfer Switch. The generator is on the other input. The switch determines which feed goes to the MH circuits, but in no circumstances should the generator power come "backwards" through the hookup cable. In any hookup where a portable generator is used to power a house there is a possibility of the power being fed out to the supply lines which is very dangerous for the linemen who are restoring power.

[Skip426]

There are special precautions to take, shutting down main breaker in S&B is important, and selecting circuits to avoid overload.
But I'm thinking the coach power cord is disconnected once the transfer switch powers the coach from the gen set; but I've never tested.

JMHO: I don't think the electrician is aware of the transfer switch function; but as I said , I've never tested.

EDIT: As always my slow typing has become apparent, others have posted the same info.

[vsheetz]

As others have said, nope.

[Dr4Film]

His information is HALF correct, only the FIRST half.

Yes, you must first cut the power to the incoming line from the pole by throwing your MAIN circuit breakers.

Next, you must have a new Outlet/Receptacle installed on the outside of your 7.5 KW generator. Then you need to have a method of connecting your house power panel to this newly installed outlet. Turn off everything in your RV including the Inverter. The only thing running should be your converter which is charging the batteries. That is not easily turned off.

Obviously, you cannot power everything in your house at the same time because there is only 7500 watts of power that you have available.

Dr4Film ----- Richard

[charlie2]

Thanks for all the replies as I'm now more informed then when I posted this question.

[Rich-n-Linda]

All you need to do this is an extension cord with male plugs on both ends. Plug one end into the coach and plug the other end into an outlet in your house. Make sure the main breaker to the power feed for the house is off before plugging in the line from the RV.

That's it. It has nothing to do with the transfer switch in the motorhome. I have done this several times at our sticks and bricks house.

You will have to do a little load shedding at the house, because you've only got 7500 or 8000 watts to power your whole house. That will run the lights and the TV but not much more. Don't try running the AC or the microwave!

[charlie2]

If you plug it into say the outside plug of the coach don't you only have like a 15 or 20 amp outlet to power the house?

[tricotec]

What I haven't seen here is the fact that the RV's power system and generator are not the same as the average home. Your home has a three-wire 220VAC feed with two hot wires and a grounded neutral and the 110V circuits are taken from both sides of that feed to the neutral wire. The RV is 110VAC only. While it might be possible to feed certain circuits in the home from an RV generator, none of the 220VAC equipment would work (AC, water heater, Range, Dryer etc), and feeding certain 110VAC loads would require some complex electrical equipment to do safely.

It would almost surely cost more in modifications to the RV and the home's electrical system to tie in the RV safely to a home than to just buy a 220VAC generator for the home and power the whole thing. Even if you did, several of your major 220VAC load could not be supplied.

[vsheetz]

Originally Posted by tricotec

What I haven't seen here is the fact that the RV's power system and generator are not the same as the average home. Your home has a three-wire 220VAC feed with two hot wires and a grounded neutral and the 110V circuits are taken from both sides of that feed to the neutral wire. The RV is 110VAC only. While it might be possible to feed certain circuits in the home from an RV generator, none of the 220VAC equipment would work (AC, water heater, Range, Dryer etc), and feeding certain 110VAC loads would require some complex electrical equipment to do safely.

It would almost surely cost more in modifications to the RV and the home's electrical system to tie in the RV safely to a home than to just buy a 220VAC generator for the home and power the whole thing. Even if you did, several of your major 220VAC load could not be supplied.

Yup, rather than make modifications and still have the limitations, I just bought a used 5500 watt generator for $325 via Craigslist. Installed a generator inlet and back fed breaker, along with a main breaker interlock to make it code compliant and safe. I keep 20 gallons of gasoline on hand, plus the ability to siphon from the dual tanks on my pickup truck. Couple years ago had a multiple day power outage - worked great, the house did not know it was on generator power instead of the POCO.

[vsheetz]

Originally Posted by Rich-n-Linda

All you need to do this is an extension cord with male plugs on both ends. Plug one end into the coach and plug the other end into an outlet in your house. Make sure the main breaker to the power feed for the house is off before plugging in the line from the RV.

That's it. It has nothing to do with the transfer switch in the motorhome. I have done this several times at our sticks and bricks house.

You will have to do a little load shedding at the house, because you've only got 7500 or 8000 watts to power your whole house. That will run the lights and the TV but not much more. Don't try running the AC or the microwave!

A dead man's cord is a very dangerous thing to have around.

[ahicks]

Originally Posted by Rich-n-Linda

All you need to do this is an extension cord with male plugs on both ends. Plug one end into the coach and plug the other end into an outlet in your house. Make sure the main breaker to the power feed for the house is off before plugging in the line from the RV.

That's it. It has nothing to do with the transfer switch in the motorhome. I have done this several times at our sticks and bricks house.

You will have to do a little load shedding at the house, because you've only got 7500 or 8000 watts to power your whole house. That will run the lights and the TV but not much more. Don't try running the AC or the microwave!

Just went through this after loosing power not too long ago. We'd been without long enough where the stuff in the freezer was in danger of thawing. I went down to Home Depot and bought 2 male 15 amp plugs, the sturdiest ones I could find, and put one on each end of a short piece of 12/2 w/g wire.

After shutting the houses main breakers off, I plugged one end of this adapter I made into an outside motor home outlet and the other end into an extension cord that I plugged into an outlet in the garage. The garage recep was chosen because I know the wire is all 12 ga from there to the main panel.

Now, from here is where things start to get a little more complicated. You need to remember that there are 2 110v legs spread out evenly within the house. One extension cord, wired as above, is not going to power both of them.... I was lucky in that all I cared about was the home refrigerator and it happened to be on the same leg as the garage recep I had chosen. If that had not been the case, I would have had to keep trying different receps until finding one on the same 110v leg as the refer.

Also, there is no way to power a 220v device using a MH generator that I'm familiar with. 2 110v legs from a generator do not make 220v! They make 110v twice... Hard for me to explain because I don't know the proper terminology, but it has something to do with phase (split phase?).

[vsheetz]

Originally Posted by Dr4Film

His information is HALF correct, only the FIRST half.

Yes, you must first cut the power to the incoming line from the pole by throwing your MAIN circuit breakers.

Next, you must have a new Outlet/Receptacle installed on the outside of your 7.5 KW generator. Then you need to have a method of connecting your house power panel to this newly installed outlet. Turn off everything in your RV including the Inverter. The only thing running should be your converter which is charging the batteries. That is not easily turned off.

Obviously, you cannot power everything in your house at the same time because there is only 7500 watts of power that you have available.

Dr4Film ----- Richard

in most areas simply throwing the main breaker is not sufficient to be POCO or code compliant. A transfer switch or main breaker lockout is required.