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Ncanchorman's avatar
Ncanchorman
Explorer
Oct 29, 2016

Autoformer

Anybody no if you can run a 50 amp power former on a 30 amp service or do you need one for each service

26 Replies

  • I have a Hughes 50Amp in the bay. It is never unplugged. Works fine on 30 amp.
  • It would depend on how the autotransformer is constructed. If it's built with a single transformer internally (which would be wired across the 240V difference between the legs of a 50A RV circuit), then it would not work on a 30A circuit. If it's composed of two indpendent 120V transformers, then it should work just fine.

    The 50A version of the Huges Autoformer does appear to have two separate transformers in its box, so it works fine on a 30A connection (and the literature for it even specifically states that this is possible and acceptable).
  • A 30 to 50 amp adapter between the pedestal and the autoformer would be needed.

    True 50 amp allows 12000 watts of power.

    30 amp allows only 3600. The autoformer will boost the voltage but the overhead from doing so is about 4%

    30 amps x 120 v = 3600 x 80% for continuous load = 2880 watts available.

    30 amps x 100 v = 3000 watts / 1.04 =~ 2884 watts X 80% for continuous load =~ 2307 watts available.
  • Ncanchorman wrote:
    Anybody no if you can run a 50 amp power former on a 30 amp service or do you need one for each service


    Not 100% sure but I would say with the proper plug adapters you could but u still would only have 30 amp service