Forum Discussion

jonlin's avatar
jonlin
Explorer
Feb 04, 2015

Generator use

Is there a problem running your generator when plugged into shore power. I have my RV plugged into shore power and would like to run the generator, is this a problem. I just like to run the generator ever so often.

Thanks,
John

20 Replies

  • MrWizard wrote:
    every few months, we get this question

    the answer is WHY take chances by being LAZY, take the two minutes to unplug shore power then start the generator, run for 30 minutes, with load
    you want to get everything mechanical warm enough to dry out any moisture and blow out any dust, collecting on any parts

    although NOT so common anymore, some transfer switches came with mechanical interlocks
    they could not switch from shore to genny if shore power was on
    the OEM transfer switch in my 95 Safari is that way


    I keep mine plugged in 24x7, but I do unplug it when I exercise the generator. Mine's an '84, but there's no lock out. Genny takes priority. If I fire it up with the shore power hooked up, it will switch to the generator power.
  • every few months, we get this question

    the answer is WHY take chances by being LAZY, take the two minutes to unplug shore power then start the generator, run for 30 minutes, with load
    you want to get everything mechanical warm enough to dry out any moisture and blow out any dust, collecting on any parts

    although NOT so common anymore, some transfer switches came with mechanical interlocks
    they could not switch from shore to genny if shore power was on
    the OEM transfer switch in my 95 Safari is that way
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    The problem is switching from one to the other HOT, by that I mean that some of the devices in your RV do not take kindly to power flickers, and this is what will happen when the transfer switch transfers.

    If heavy current is flowing, there will be arching on the contacts in the transfer swtich, this can weld them in one or the other position and leave you in the dark.. Air conditioners the compressor can stop and then try to restart with a full head of pressure (They are not designed to do this)

    Solution, turn off A/C.s water heater and such (other big loads) turn off main breaker, wait 2 mintues, start generator, wait one more minute and turn everythign back on in the reverse order of turn off.

    Same when you shut down,, Same proecdure save for "Turn off" generator. (You can do that soon as you trip the main breaker) wait 3 full minutes from OFF to ON on the main breaker.
  • Unfortunately, you likely won't know if it is a problem until it's too late. Unplug.
  • I have a transfer switch on mine, I exercise my Generator once a month I unplug from shore power before starting the Generator, why take a change of something happening. Roy
  • Most transfer switches are wired for generator priority—in other words, once the generator is running, the shore power is disconnected and the coach is powered by the generator alone. (This is assuming you don't have some sort of a fancy EMS, in which case the sky's the limit for what gets powered by what when.)

    I don't know why the house outlet breaker would trip assuming the transfer switch is wired and operating correctly. If it's a GFCI breaker and the neutral line isn't being switched properly, the GFCI would probably pop because the RV generator has ground and neutral bonded together. The transfer switch should be switching the neutral with the hot line(s). If the hot is not being switched, you have even bigger problems and would probably already know that something very bad was happening.

    As was mentioned, switching between shore and generator power under load is not a good practice.
  • We have an aux switch inside to start the generator without unplugging from power. We also have an automatic transfer switch. We first shut off the frig, water heater etc - let generator run for a minute or two and then start adding thing to the load. The generator DOES get exercised as you can hear the difference as you add load to it. It does not just sit and idle.
  • Effy's avatar
    Effy
    Explorer II
    Why would you want to do that? I assume so you don't have to unplug to exercise the Gen?? If you really want to exercise the gen it should be under a decent load which won't happen if you are plugged in. It will just idle. You need to load the gen which means letting it power your coach.

    Modern transfer switches are designed to mitigate a problem but I wouldn't tempt fate. The result could be really bad and expensive and not really get the results you want anyway.
  • If I do that for some reason it blows the circuit breaker on the house outlet. Because of that I have to unplug first. My RV does have the auto transfer switch and I have had others tell the same story.
  • If your coach has a transfer switch, it is most likely wired to give the generator priority. So be sure to reduce the electrical load before starting. It's really hard on the transfer switch and the generator to switch when heavy loads are applied.