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howardwheeler's avatar
howardwheeler
Explorer
Jul 06, 2018

Balancing loads on each leg of 50 amp service

As I was working on my generator ( another story on a different thread), I came across the reality that both of my ACs were on the same leg of my 50 amp service. It has been that way from the factory (15 years!). When on shore power the 50 amp leg is sufficient to run both, which is why I’ve never noticed it. I have a progressive dynamics ems and it confirmed that all my amp draw was on one leg. So I’ve begun by switching my second AC onto a different leg. Now, with the ACs running, the leg that supplies the main AC is drawing about 17 amps and the second leg around 14. Anybody have any advice on how to further balance the loads? I found it all out because when I was testing my generator, which has a 20 and a 30 amp breaker, one of the breakers would trip and both ACs would shut down. Now my generator (now finally fixed!) can run both ACs. The main AC, the inverter/charger and the microwave is on the first leg, whereas the second AC, the washer/dryer and some plugs are on the second. The electric heater for the hot water is on leg one also. I don’t know how much it draws but being resistance heat it can’t be negligible.

10 Replies

  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Jul 06, 2018
    Camping world did that to me when they installed my INverter.
    Oh, and they also messed up an oil change (how do you mess up an oil change.. Wrong oil of course)

    THey also missed a step on the oil change.
  • howardwheeler's avatar
    howardwheeler
    Explorer
    Jul 06, 2018
    Thanks. I got out the original wiring diagram for the trailer last night (Alpenlite is good about thorough construction documentation) and sure enough the circuit breakers are shown to be the way I now have them with the second AC on the second leg. From the factory they switched places with the electric element of the hot water heater. So now it’s the way it was originally designed. It’s been like that for fifteen years! The only way it would show up as a problem was if I ran both ACs off the generator.
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Jul 06, 2018
    YOu are only about 1.5 amps from balanced.
    Fridge is about 3 amps so that would simply move the problem.

    Your TV's might be closer to 1.5 amps but odds are they too will hit 3-4 total.

    You are basically balanced. I would consider where you are now to be excellent.
  • howardwheeler's avatar
    howardwheeler
    Explorer
    Jul 06, 2018
    I have a residential fridge—an inverter compressor Samsung—so it runs off the inverter leg, which I have on leg one. That means it will be on the thirty amp breaker when running off the generator. It seems that has to be on the bigger breaker.
  • DrewE's avatar
    DrewE
    Explorer II
    Jul 06, 2018
    westend wrote:
    Balancing between the two legs is the way to go. 17A on one and 14A on the other is fairly good. Your water pump or a circulating fan would use about 3A.


    The water pump is a 12V load, so would be accommodated in the converter or inverter-charger load. I doubt it would amount to 350 VA. It might use 3A at 12V, or somewhat more, when running.

    An absorption fridge on AC power uses about 3A or so.
  • westend's avatar
    westend
    Explorer
    Jul 06, 2018
    Balancing between the two legs is the way to go. 17A on one and 14A on the other is fairly good. Your water pump or a circulating fan would use about 3A.
  • MrWizard's avatar
    MrWizard
    Moderator
    Jul 06, 2018
    don't know if you ever boondock

    but i would but the LR/front A/C on the 20amp circuit
    and the bedroom/rear A/C on the 30amp side, with the MW etc..

    come time to cook in hot weather
    being able to keep the front A/C on while using the MW etc, and turning off the rear A/C if loads need to be shed while making coffee or using the MW etc
  • howardwheeler's avatar
    howardwheeler
    Explorer
    Jul 06, 2018
    Yes. When running the generator the water heater electric element is switched off. Runs only on propane.
  • time2roll's avatar
    time2roll
    Nomad
    Jul 06, 2018
    I would put the MW/inverter on the 30 amp side and the WH on the 20 amp side but turn it off electric if running the generator. WH is 12 amps.

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