Running the house with my motorhome genset?

[Ghost]

I have a 7kw Onan/Cummins genset installed in my rig.

I am curious to know if there is a method by which I can use it to run my home during a power outage.

Anyone done this?

If so - was Cummins able to provide you with a power outlet panel? Lockout switch?

Thanks,

Kent

[dssl]

I haven't done it with my motorhome, but did set up my house for a Small generator.

The 7kw is likely only 120 ( at least true on mine).first you need to install a receptacle in the RV. A 10/3 plus ground to a twist lock would be the best way to go. You could tap off anywhere from after the generator to the transfer switch, whatever is easiest.

On the house side you need a power inlet box and room for a double pull 30 amp breaker. And a 30 twist lock cable

They make what they call a generator interlock kit. This is basically a mechanical thingy that makes it impossible to have the main on at the same time as your generator feed breaker. Mostly the generator feed breaker needs to be the upper most breaker on the right hand side of the main panel. The generator interlock kits can be found on Amazon and are dependent on the brand and type of breaker box.

Without the interlock kit you would need to be very careful to never have both the generator and the house main on at the same time, since that could cause lots of damage. If it's ever going to get inspected it probably needs a generator interlock kit.

Hope that helps.

[MrMark52]

You effectively need a transfer switch that is set for the normally open contacts to be wired to the house, and the normally closed contacts to be wired to the normally open contacts - and the coil operator wired to the house electric.

Alternatively - one of the controllers for the various brands of whole house gensets could be used although they usually have the ability to start the genset during a power outage.

But to be honest - you’ll likely kill that generator pretty quickly if you put the house load on it without isolating the high current loads like electric ovens, electric water heaters, A/C condensing units, electric furnaces, electric cooktops away from the house panel.

And doing any part of this wrong can be extremely dangerous.

[hclarkx]

Pretty well covered in the above posts. Not a simple matter.

If the idea remains interesting, the next step would be find the model number of the generator and look up the manual on the interwebs if you don't have one (complete with electrical specs and diagrams). This will tell you whether the generator is 120/240 split-phase and thus suitable for powering the house in a manner similar to a proper backup generator. ((my guess from this page is that it is not .... https://www.cummins.com/generators/onan-qg-7000 ... download the RV Generator Handbook))

I'd lean away from the idea if the generator doesn't inherently output split-phase. If it does, I'd want a manual "throwover" in the RV near the generator so the generator is powering only the RV or only the house.

[dssl]

You can't run an entire house off a 7k generation. Most Onan 7k generators are only 120 volts(My Onan QG7000 is) plus your house requires way more power.

So, what can you run off a 7k generator? Lights, computers ,refrigerators, freezers, microwave. A toaster oven, a coffee maker. Maybe a space heater. Probably not all those together. Nothing 240v so no electric water heatver, stove,oven or air conditioner...no heater unless it's gas or oil and only urs 120v.

The suggestion of a transfer switch is gong to add lots of.cost. and for a 7kw generator from your RV is going to be hard to justify. A generator interlock kit is cheap and will allow you to utilizeyour generator during a power outage easily.

[dssl]

You can't run an entire house off a 7k generation. Most Onan 7k generators are only 120 volts(My Onan QG7000 is) plus your house requires way more power. If you have a bigger generator common on diesel motohomes they would be 240v, which could open up some more of your house.

So, what can you run off a 7k generator? Lights, computers ,refrigerators, freezers, microwave. A toaster oven, a coffee maker. Maybe a space heater. Probably not all those together. Nothing 240v so no electric water heater, electric stove,electric goven or air conditioner...no heater unless it's gas or oil and only uses 120v.

The suggestion of a transfer switch is gong to add lots of.cost. and for a 7kw generator from your RV is going to be hard to justify. A generator interlocking kit is cheap and will allow you to utilize your generator during a power outage easily.

[tap4154]

My MH is in the backyard, and on the rare occasions when I have an outage that lasts hours, I just run a heavy duty cord into the kitchen to keep the fridge going with my Onan 4K. I can run the TV and Wi-Fi off it as well, but usually don't.

[hclarkx]

Originally Posted by tap4154

My MH is in the backyard, and on the rare occasions when I have an outage that lasts hours, I just run a heavy duty cord into the kitchen to keep the fridge going with my Onan 4K. I can run the TV and Wi-Fi off it as well, but usually don't.

I do the same, though my source is the solar+batteries+inverter in a fifth wheel. If there's not enough sun, a Honda EU2000i generator (1600 Watts) recharges the batteries.

[n2zon]

Originally Posted by dssl

You can't run an entire house off a 7k generation. Most Onan 7k generators are only 120 volts(My Onan QG7000 is) plus your house requires way more power. If you have a bigger generator common on diesel motohomes they would be 240v, which could open up some more of your house.

So, what can you run off a 7k generator? Lights, computers ,refrigerators, freezers, microwave. A toaster oven, a coffee maker. Maybe a space heater. Probably not all those together. Nothing 240v so no electric water heater, electric stove,electric goven or air conditioner...no heater unless it's gas or oil and only uses 120v.

The suggestion of a transfer switch is gong to add lots of.cost. and for a 7kw generator from your RV is going to be hard to justify. A generator interlocking kit is cheap and will allow you to utilize your generator during a power outage easily.

I beg to differ on the power requirements for a house always being greater than 7KW.

Before the heat pump was installed, our backup was a 1976 Onan BGA 5KW genset. We had a gas dryer, water heater, and range; and an oil furnace. That old BGA has 240V capability.

Once the OP understands the power requirements for *his* house, the next obstacle is bigger. The QD7K and 7.5K gensets are both, I believe, 120V only. In addition, they are not designed for the inrush loads that can be imposed when a transformer needs to be saturated at the "wrong" point in the sine wave cycle. You can solve both with an autotransformer, an inrush limiter, and soft starts on the remaining motors, but Onan technical support strongly recommended against it when I spoke to them a couple of years ago. Their inverters just aren't designed for it.

We are currently looking at 24K Onan gensets because our new heat pump and hybrid water heater require much more than the old 5K genset can support.

[1stimerveer]

We made it through Hurricane sandy without power for 14 days, on a 5500/6250 watt 220 V coleman. It ran our lights, furnace, freezer, sump pump, and our well pump.

Had to shut off breakers to the other devices to run our well pump. When finished with the well pump, we shut off its breaker and turned the others back on again.

It is an open frame generator and after 14 days it took me a long time not to cringe every time I heard a small engine running...

[ArtJoyce]

I'm interested in this conversation. I have a 6.5kw propane
generator in the MH. Have thought about it several times. My house only has 4 appliances that are 240V. AC unit 1 & 2 and dryer 1 & 2. The rest of the house is NG (furnace, stove and oven and water heater)

Questions I have?
- Somehow you need to tap into the MH
- I need a disconnect switch in the house

[MrMark52]

I’ve been away from the NEC for a few years, but most homes today have an at least 200amp electrical service, and I think the new standard is 250amps.

A 7kw generator, whether 120 volts 1 phase, or 2 legs of phase opposed 120 volts (to get 240 out) will not effectively power a 200 amp panel, much less a 250 amp panel.

Those who want to do this are to be commended for seeking a means to use their MoHo generator in times of need - and that’s a good thing.

But seeking advice on a MoHo/RV website of how to do it is not well advised. I would urge you to contact a qualified electrician to determine the feasibility of doing this.

[Alpine36]

It can be done, but you’re only getting one leg of 120v. Aside from the transfer switching requirements, some re-arranging of house circuit breakers will likely be in order.
During our last major power outage we simply ran an extension cord out of the Coach basement power outlet to the house for a couple lights and the fridge/freezer. We just stayed in the coach, with all the creature comforts of home. If you experience frequent power outages consider investing in the appropriate generator with auto start and ATS, professionally installed. That way your covered if the coach is not home…
Please do not consider internet advice involving suicide cords or manually back feeding service panels. The IBEW thanks you.

[dssl]

Originally Posted by ArtJoyce

I'm interested in this conversation. I have a 6.5kw propane
generator in the MH. Have thought about it several times. My house only has 4 appliances that are 240V. AC unit 1 & 2 and dryer 1 & 2. The rest of the house is NG (furnace, stove and oven and water heater)

Questions I have?
- Somehow you need to tap into the MH
- I need a disconnect switch in the house

In the motorhome I think the easiest place to tap is probably going to be at the transfer switch. You can basically run a small piece of conduit from the transfer switch to a small box with a 30 amp twist lock receptacle, using 10 guage wire.

On the house side you need room for a double throw 30 amp breaker in your main panel. Hopefully you can rearrange your breakers so that you can use a generator interlock kit for that new 30 amp double pull(on mine it needed to be the top right most breaker). From the 30 amp breaker you need to run 10 guage thhn wires through a conduit to a generator inlet box. You also need to add neutral and ground.

To connect the power you need a 30 amp twist lock cable between your new motorhome receptacle and the generator inlet box.

To activate it you first turn of your main, and then turn on the new 30 amp feed breaker. The interlock kit prevents you, or anyone from turning on the main and the breaker for the generator at the same time. Without the interlock kit it would still work, but you would need to be very careful to NEVER turn on the main at the same time as the breaker to the generator.

If you are handy , and comfortable around electrical equipment then this isn't near as hard as some people make it out to be. If you aren't comfortable doing this then hire an electrician.