Announcement

Collapse
No announcement yet.

Can we use "Cheater" electric adapters with these rigs

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Can we use "Cheater" electric adapters with these rigs

    Well another question from the newbie. So we purchased one of these cord adapter things to use when we are in a site that doesn't offer 50 amp service. It is a "Y" shaped deal that allows me to plug in to the pedestal using 2-30 amp plugs or a 30 amp and a 20 amp and that runs those lines out to the 50 amp plug to which I connect the RV.

    I have found myself in a sitution where this would have been nice twice. One with a 30/30 option and once with a 30/20 option. However, as far as I can tell from the RV side, the system only recognized 30 amp service. Is this correct? Is there a magic switch or something special I need to do in order to make this work?

    Thanks so much.

    Michael
    Michael and Katherine (Moe and Flo on the go)
    Full-time since March 2017

    2016 F450, DRW, Crew Cab, Goodyear airbags, TrailerSaver TSLB2H hitch
    2014.5 Elite Suites 38RESB3, vanity slide, customized. #6987

  • #2
    The power management system is looking for 240 VAC between the L1 and L2 legs as an indicator of 50 amp service. If the 30 amp and 20 amp receptacles you plug into both use L1 as their single hot leg, the power management system will see 0 VAC between L1 and L2 in the breaker box of the RV and will default to 30 amp service.

    True 50 amp service has a total theoretical power capacity of 120 VAC x 50 amps/hot leg x 2 hot legs = 12,000 watts. Plugged into 30 and 20 amp shore power pedestal outlets, the cheater could deliver a maximum of (120 VAC x 30 amps) + (120 VAC x 20 amps) = 6,000 watts. Better than the 3,600 watts of 30 amp service, but only half the theoretical ampacity of true 50 amp service.

    Also, be aware that some RV parks do not allow the use of these cheater boxes.

    Rusty
    Rusty & Sandy Creekmore
    2 Shelties - Coby & Callie + Conner the Campground Cat

    Prior - 2004 MS 36RE3 #1291; Current - 2014.5 MS 38RSSA #6972

    2016 Ram 3500 DRW Longhorn Crew Cab Long Bed, 4x4, 385/900 Cummins, Aisin AS69RC, 4.10, B&W RVK3600 hitch

    Comment


    • #3
      Rusty,
      That is a darn good explanation of how those cheaters work--thanks.
      Joe
      2005 36TK3 #1869
      2010 F450 Lariat

      Comment


      • #4
        So, if I understand correctly, the juice is there but the system doesn't recognize it. That being the case, will the PMS still shed loads as if there were only 30 amps?

        Regards.
        Michael and Katherine (Moe and Flo on the go)
        Full-time since March 2017

        2016 F450, DRW, Crew Cab, Goodyear airbags, TrailerSaver TSLB2H hitch
        2014.5 Elite Suites 38RESB3, vanity slide, customized. #6987

        Comment


        • #5
          Yes, it will behave like it has 30 amp service. I have this problem at our RV storage lot where the owner has "miswired" 50 amp service in one receptacle we sometimes use. Rather than pull 2 hot legs to the receptacle, both hot legs in the receptacle are taken from a single hot leg supply and are therefore in phase - the PMS sees 0 VAC between L1 and L2. The PMS will only allow us to run 1 A/C when plugged into this receptacle - it won't start the 2nd A/C compressor and displays 30 amp service.

          Actually, that's a safeguard as a miswired 50 amp service such as this could overload the shore power cord's neutral leg under maximum load conditions, but unless the PMS sees 240 VAC between L1 and L2, it will function as if 30 amp service is present.

          Rusty
          Rusty & Sandy Creekmore
          2 Shelties - Coby & Callie + Conner the Campground Cat

          Prior - 2004 MS 36RE3 #1291; Current - 2014.5 MS 38RSSA #6972

          2016 Ram 3500 DRW Longhorn Crew Cab Long Bed, 4x4, 385/900 Cummins, Aisin AS69RC, 4.10, B&W RVK3600 hitch

          Comment


          • #6
            Please excuse me if this comment is from a poor memory, but for some reason, I recall someone stating that the 30/20 "Y" configuration won't work if the park's electrical pedestal has a GFCI for the 20 amp circuit.

            Terry
            Terry and Jo

            Mobile Suites 2010 38TKSB3 #5332
            2008 Ford F450
            2017 Ford Expedition XL as Tag-along or Scout

            Our Photos on Smugmug

            Comment


            • #7
              That's correct. A GFCI operates by detecting ANY difference between hot leg and neutral leg current. If all the current going out the hot leg doesn't return on the neutral leg, then the assumption is that the missing current could be going through an individual to ground (thus the name - ground fault circuit interrupter).

              These cheaters tie the neutrals and grounds from the 30 amp and 20 amp services together since the cheater's 50 amp output receptacle has only 1 neutral, 1 ground and 2 hot legs. This shared neutral will NOT return the precise amount of current to the GFCI 20 amp outlet as the hot leg is providing, so the GFCI will trip.

              Rusty
              Last edited by RustyJC; 04-15-2015, 04:05 PM.
              Rusty & Sandy Creekmore
              2 Shelties - Coby & Callie + Conner the Campground Cat

              Prior - 2004 MS 36RE3 #1291; Current - 2014.5 MS 38RSSA #6972

              2016 Ram 3500 DRW Longhorn Crew Cab Long Bed, 4x4, 385/900 Cummins, Aisin AS69RC, 4.10, B&W RVK3600 hitch

              Comment

              Working...
              X