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jeffo's avatar
jeffo
Explorer
Jul 15, 2018

Add Plug To Generator

I have an Onan 5500 watt Gen on my class A. It doe not have an external plug that I can use without going thru the breaker box on the RV. I would love to be able to use the gen to power some things in the house if our electricity goes out for any length of time without powering anything in the RV. I was thinking I could install a manual transfer switch to use in this event. I do not want to get into anything to deep that may harm the gen. This would only be used maybe once a year.
  • What I did next to our home breaker box was install 3 outlets. They were directly powered by the breakers for the kitchen fridge outlet, kitchen lights, and master bath lights (and labeled as such). Directly below each outlet I surface mounted a 2 x 4 handy box. Out of those came a short piece of 12 gauge extension cord type wire (with plug) that connected to the house wiring for the matching circuit. These were normally plugged into the outlets above them. In case of power failure, I would unhook them and plug them into a heavy duty extension cord connected to the RV so they could easily be powered by the RV genny and there would be no possibility of back feeding into other circuits. This worked very well through many hurricanes. I like the idea of using the RV for emergency power as it is parked outside the house to protect against CO poisoning. Most RV gennys are quieter than the average home generator (except the more expensive ones).
  • I added one 15 amp outlet to mine, wired in in parallel with the main wiring. Just used it to run a small compressor I mounted behind the propane tanks.

    Check your generator, if its an Onan 550 Marquis Gold (popular model) and it's only 30 amp, then you'll have a spare 30 amp circuit on the generator that is not being used. You can grab that an wire in another 30 amp outlet.
  • thats true Dutch good idea
    another outlet, say a 3 wire 120v twist lock
    wired to the the main 'pair' of wires from the 30amp Onan circuit breaker

    the RV needs to have electric to keep the converter going to keep up the RV battery for the generator

    forgot about that, when doing the switch wiring instructions
  • yes its possible, you will need a 30amp double pole double throw toggle switch

    for manual switching, between RV use and outlet use for the house

    manual switch not automatic,
    can't be automatic, because you will use generator for RV or house
    so there is NO automatic setup that would not always go to the default when generator is running

    how much do you know about 120v power, and DPDT switches

    you need to open the junction box where the Onan wiring connects to the RV

    you need to see 5 wiring connections, (2) sets of black wires, (2)sets of white wires, and one set of green wires

    if you see this, you have a 30a circuit for the RV, a second 20a circuit for the second A/C

    so you can interrupt (1) circuit and run it thru the switch
    connecting power in, RV and outlet all to the switch
    you will need a box for the outlet
    and probably one for the big DPDT switch

    your RV outlets should be 15a duplex outlets on a 20a breaker
    the easiest thing would be to replace the outside patio outlet with a 20a duplex outlet,

    and use a 12ga 20a extension cord to feed the temporary power to the house
  • A couple of questions.
    Is it 120 volt only, or 120/240 volt?
    What does it use for a transfer switch?
  • That is exactly what I did, But it its seems a shame that I have 5500 watts of power and can only use it thru a 15 amp plug.
  • Your generator must power the outside "plug"...presuming you have one (for the patio lights, etc.)start the genny and put an extension cord on that.

    No mods needed. It worked for me with "Sandy"...power went out for 4 days. 50 ft of 12 Ga. extension cord...alternate between the lights & TV...the kitchen fridge and garage freezer. Went outside to use the propane stove and bar-b-q grill. (All electric house). We survived just fine.

    Then....I bought a 8,000 watt generator and had an electrician install a transfer switch. SO MUCH better than that PITA(but workable )extension cord. method.

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