Using RV generator as backup for house?

[coolmom42]

My electricity is still on in Middle TN, no worries. But that may not always be the case in the future!

If I have a transfer switch properly installed, is there any reason I can't use the RV generator to power my house?

Water heater and range are gas. City water supply, no well pump. Gas furnace with (and this is the critical thing) an electric blower. 1 refrigerator, 1 small chest freezer. Lighting is mostly LED.


Google tells me that the furnace blower uses around 400 Watts. I'm going to check with the HVAC dude.


The only downside is having the generator running fairly close to the house, but I have multiple CO detectors, and probably would be able to leave it off most of the night.

Any input?

[opnspaces]

coolmom42 wrote:

time2roll wrote:
3000 watts should run that house fine. Electrician will probably put the critical items on a 120v sub panel in addition to installing a switch and a power inlet to connect power.

My generator is 4000 watts. It would be nice to be able to run the whole house, including TV & internet. Not essential, but nice.

Just wanted to touch on this because I had the same thoughts about how cool it would be to keep the internet up. The problem is unless you are tethering the internet through cellular, once the power goes out the internet goes out too. Yes I can get my cable modem back up and running on the generator. But after the signal leaves my modem it is dropped by some unknown system down the line because it has no power either. So in reality once the power goes out the internet goes with it.

[K_and_I]

I have a 9,000 watt continuous (12,000 start) and it won't run my heat pump, so I just plug in a couple of portable heaters. If you run extension cords that would be easy enough. I understand your desire to not run cords.

[ktmrfs]

coolmom42 wrote:

ktmrfs wrote:

Rover_Bill wrote:

time2roll wrote:
3000 watts should run that house fine. Electrician will probably put the critical items on a 120v sub panel in addition to installing a switch and a power inlet to connect power.

This is the switch that I had installed in my house for use with my 3K inverter generator. Works great and allows you to watch the wattage being drawn on each leg.

I think the link you provided is for a 240V input, there is also a 6 circuit 120V 30A available from the same mfg. That's what I have.

If all you want to do is power one or two circuits this is another option.

https://ezgeneratorswitch.com/

If you go the transfer switch route make sure it is compatible with your generator. unbonded neutral generators (ground neutral not bonded) transfer switch wiring is different than a bonded neutral generator.

EZgenerator switch can be configured for both, IIRC the other 6 circuit transfer switch is only configured for use with an unbonded neutral generator. Many if not most portable generators are unbonded neutral.

My generator is the 4KW Onan built into a motorhome. How do I determine whether the neutral is bonded or unbonded?

plug in one of the 3 prong circuit testers on a 120V output plug. Turn on the genset. If is says open ground, it's unbonded, if it indicates everything is OK, then ground neutral are bonded.

Or if you have a ohmeter, witht the generator OFF check for continuity between neutral and ground. If it is an open circuite, unbonded, if it is a short circuit (few ohms) then it is bonded.

[Gdetrailer]

coolmom42 wrote:

enblethen wrote:
To determine grounded neutral, you need to isolate genset out put, start genset, you should have 120 volt between both neutral and ground. You should have continuity and no voltage between neutral and ground.
I am guessing you have a transfer switch in your rig!

Yes, in that the generator automatically feeds the power panel without plugging the power cord into the generator. (Although the previous owner told me that was necessary, he was wrong.)

I don't think that would have any impact on connecting to the house panel.

A lot of confusing stuff going on here.

Are you wanting your RV shore cord to double as a "backfeed" so you do not need to run an extension cord?

If so that can present a lot of problems.

The simplest way to go about this provided your gen is wired as 240/120V (which is required to run your home furnance in this case) would be to have a 240/120V 50A outlet wired to your gen, bypassing the ATS of the RV..

Then on your home you install a proper 240/120V gen interface inlet.

That inlet can be wired to your home main breaker panel provided you have space for the required two pole breaker AND you can get a gen interlock kit for the panel. This will require moving breakers in the panel so the gen breaker and the main panel breaker can be serviced by the interlock kit.

Now, all you will have to do is connect a 50A 240/120V extension cord to the gen outlet on the RV, start the gen and flip the breaker interlock to gen..

However, that ALL hinges on IF your gen is wired for 240/120..

MANY RV gens are only wired as 120V basically shooting this idea dead on arrival..

If your RV gen is not wired for 240/120V operation then I would suggest just buying a separate portable gen that does support 240/120V but do get the gen interlock and the gen input installed.

[Gdetrailer]

coolmom42 wrote:

time2roll wrote:

coolmom42 wrote:
I need to run the furnace blower. No way to plug it into an extension cord.

Is it hardwired? What are the electrical requirements?

I have a dozen home furnaces and they all plug into a standard wall outlet up in the attic, garage or heater closet.

My furnace & blower are outside in what is called a "GasPack" unit. It's the only configuration of central heat/ac that will work in my 1960s ranch style house with crawl space and low attic space. They are pretty common around here.

Your most likely going to need 230V to run a Gas pack furnace..

Looked up gas packs and found a Goodman 2T with 40K BTU gas furnace and that one requires 208V or 230V for the fan motor..

Found that info HERE

For those who don't understand what a gas pack is they look like this photo for outdoor versions and are "all in one" A/C with gas furnace..



I HIGHLY doubt that it is "plugged in" and most likely is hardwired to at least a outdoor service cutoff disconnect switch..

[time2roll]

coolmom42 wrote:
It's a gas furnace with electric blower, in a package unit with the AC, which uses the same blower. I am quite familiar with the utilities in my home.

If that is the case you should not have the huge power requirement but may require 208-230v.
Generally that will be a dedicated circuit so you could pull the wires off the main panel and extend to a generator running close to the panel.

Yes a transfer switch and all is better but if you need heat on today...

[coolmom42]

enblethen wrote:
To determine grounded neutral, you need to isolate genset out put, start genset, you should have 120 volt between both neutral and ground. You should have continuity and no voltage between neutral and ground.
I am guessing you have a transfer switch in your rig!

Yes, in that the generator automatically feeds the power panel without plugging the power cord into the generator. (Although the previous owner told me that was necessary, he was wrong.)

I don't think that would have any impact on connecting to the house panel.

[coolmom42]

time2roll wrote:

coolmom42 wrote:
My furnace & blower are outside in what is called a "GasPack" unit. It's the only configuration of central heat/ac that will work in my 1960s ranch style house with crawl space and low attic space. They are pretty common around here.

I think that is a heat pump, not a furnace.
Yes you need to adjust the power requirements accordingly.

It's a gas furnace with electric blower, in a package unit with the AC, which uses the same blower. I am quite familiar with the utilities in my home.

[coolmom42]

SAR Tracker wrote:
We usually lose power a couple of times a year (winter, wind, fires, ect.). Our 5500 watt portable provides plenty of power, if used judicially. An extension cord run into the house to a power strip for the TV (on cable, interestingly, cable never goes out when the power does - underground), run the refrigerator about every 4 hours, the chest freezer is good for at least 12, laptops can run with the TV. A wood stove heats at least the living room, and eventually the whole house. HWH and furnace are both 240, neither work on gen power.

Heat is my primary concern. I've looked at gas heaters, wood stoves, etc but really don't have a suitable place in the house to put one. All the other stuff is gravy. But nice to have.

[coolmom42]

valhalla360 wrote:

Dutch_12078 wrote:
Be aware many RV generators do not provide 240 volts, so you won't be able to run any appliances that call for it, such as most deep well water pumps, etc.

Since the OP specifically covered the water supply as being city water, not an issue.

To the OP: You are golden with what you want to do. Just a question of how much prep work you want to put in from minimal and run extension cords to a built in system with automatic transfer switch feeding a subpanel for the items you want to run off the generator. Since you are asking the question, I'm going to say, get a professional to set it up for you as you likely don't have the knowledge to do it right.

I understand the principles. The wiring is probably beyond me. I definitely want a built-in system. If the weather is nasty, I don't want to be dragging extension cords on the ice.

[enblethen]

To determine grounded neutral, you need to isolate genset out put, start genset, you should have 120 volt between both neutral and ground. You should have continuity and no voltage between neutral and ground.
I am guessing you have a transfer switch in your rig!

[time2roll]

coolmom42 wrote:
My furnace & blower are outside in what is called a "GasPack" unit. It's the only configuration of central heat/ac that will work in my 1960s ranch style house with crawl space and low attic space. They are pretty common around here.

I think that is a heat pump, not a furnace.
Yes you need to adjust the power requirements accordingly.

[coolmom42]

ktmrfs wrote:

Rover_Bill wrote:

time2roll wrote:
3000 watts should run that house fine. Electrician will probably put the critical items on a 120v sub panel in addition to installing a switch and a power inlet to connect power.

This is the switch that I had installed in my house for use with my 3K inverter generator. Works great and allows you to watch the wattage being drawn on each leg.

I think the link you provided is for a 240V input, there is also a 6 circuit 120V 30A available from the same mfg. That's what I have.

If all you want to do is power one or two circuits this is another option.

https://ezgeneratorswitch.com/

If you go the transfer switch route make sure it is compatible with your generator. unbonded neutral generators (ground neutral not bonded) transfer switch wiring is different than a bonded neutral generator.

EZgenerator switch can be configured for both, IIRC the other 6 circuit transfer switch is only configured for use with an unbonded neutral generator. Many if not most portable generators are unbonded neutral.

My generator is the 4KW Onan built into a motorhome. How do I determine whether the neutral is bonded or unbonded?

[coolmom42]

time2roll wrote:
3000 watts should run that house fine. Electrician will probably put the critical items on a 120v sub panel in addition to installing a switch and a power inlet to connect power.

My generator is 4000 watts. It would be nice to be able to run the whole house, including TV & internet. Not essential, but nice.

[coolmom42]

time2roll wrote:

coolmom42 wrote:
I need to run the furnace blower. No way to plug it into an extension cord.

Is it hardwired? What are the electrical requirements?

I have a dozen home furnaces and they all plug into a standard wall outlet up in the attic, garage or heater closet.

My furnace & blower are outside in what is called a "GasPack" unit. It's the only configuration of central heat/ac that will work in my 1960s ranch style house with crawl space and low attic space. They are pretty common around here.