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btcruzer's avatar
btcruzer
Explorer
Jan 06, 2015

not really technical but ???

while checking out a new to us rv, I noticed the Onan 5500 had two (2) circuit breakers mounted above the prime/start switch. One breaker was 30 amp and the other was 20 amp. I'd been running the generator and everything inside seemed to work. Only the 30 amp breaker was on. What is the 20 amp breaker for? Is there possibly an outlet mounted on the generator? I looked but didn't find one. I'd really like that situation as I would prefer to use an extension cord to bypass all the internal wiring for outdoor cooking etc. I had noticed there are no outside outlets on this RV. But, I did find an outlet mounted inside a passenger side cargo compartment. It would be just spiffy if that 20 amp breaker powered that outlet. I know, " simple enough to check" but it is 11 PM and 20 degrees. BTW, the unit is a 2003 Fleetwood Flair if anyone can answer before I go out tomorrow. Thanks
  • btcruzer's avatar
    btcruzer
    Explorer
    Jan 07, 2015
    the controls for the ACs look to be factory. and Wa8yxm you're probably right. This rig does not have a transfer switch, just the ole fashioned plug the shore power cable into the generator outlet. When we ran the things before delivery, first we ran on shore power and the guy demonstrated the load shedding. One or the other but not both would run depending on the temp settings. We then ran the generator and both ACs would run... heck, who knows, I might have knocked the ckt. breaker to the off position while cleaning up the generator. Guess this has been much ado about nothing --- but now I know before I need to use AC.
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Jan 06, 2015
    BT from your last post it is 100% the 2nd breaker is for the #2 (usualy rear) A/C.

    The power manager (Elaborate load shedding device, my name for it) failed to sense power on the 2nd line so it ran the system as though on shore power.

    With the breaker on the power center should show "GENERATOR" on its display and the Rear AC runs when it wants to run, never gets shed..

    I have a 50 amp rig so mine works different, but I have studied 30 amp systems and ... well.. that is how it works.
  • turbojimmy's avatar
    turbojimmy
    Explorer
    Jan 06, 2015
    btcruzer wrote:
    okay, that sounds kinda right. There are 2 ACs. And the shore power is only 30 amps. But both seemed to work when we tried everything in warmer weather. Both on shore power and generator. The ACs are controlled by an elaborate paned that features "load shedding" and prevents one AC from running while on shore power. Seems there is a feature that selects one or the other depending on where cooling is needed. I don't know when the 20 amp breaker was tripped, probably have to wait for warmer weather to check this out.

    After I thought about it, I realized that "they" probably wouldn't install an outlet that is "hot" only when the generator is running.


    I'm not sure how old your RV is, but it's possible that someone installed the load shedding system aftermarket. The 2 breakers on the generator, as others have said, are to feed the breaker panel (30 A) and the 2nd A/C (20 A). If both A/Cs work on both shore power and generator and with the 20A breaker tripped I would venture to guess someone installed the load shedding system aftermarket. It's a nice feature. I can only run my 2nd A/C unit with the generator (now you've got my wheels turning....).
  • btcruzer's avatar
    btcruzer
    Explorer
    Jan 06, 2015
    okay, that sounds kinda right. There are 2 ACs. And the shore power is only 30 amps. But both seemed to work when we tried everything in warmer weather. Both on shore power and generator. The ACs are controlled by an elaborate paned that features "load shedding" and prevents one AC from running while on shore power. Seems there is a feature that selects one or the other depending on where cooling is needed. I don't know when the 20 amp breaker was tripped, probably have to wait for warmer weather to check this out.

    After I thought about it, I realized that "they" probably wouldn't install an outlet that is "hot" only when the generator is running.
  • wildtoad's avatar
    wildtoad
    Explorer II
    Jan 06, 2015
    copeland343 wrote:
    Second A/C is on the 20amp breaker if you have one. Is RV 50amp or 3amp.


    Since it has a 5500 chances are it either has or is pre-wired for the second AC and there should be a switch somewhere for controlling the second one.
  • WyoTraveler's avatar
    WyoTraveler
    Explorer
    Jan 06, 2015
    Years ago most RVs only used 30 amp plugs. Don't remember which year they went to 50 amp. My 1989 Pace Arrow only had a 30 amp plug. The Onan generator was still 50 amp. Both A/Cs would run on the generator but only one would run on shore power. Fleetwood had a switch in a kitchen cabinet and you could select which A/C you wanted.

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