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Canadian_Rainbi's avatar
Jan 20, 2017

UPDATE Splicing 30A plug to 50 amp cord

First of all, don't tell me to buy a new 50A plug. We are in southern Mexico and there are none to be had.

On Amazon US I have seen them for under $20.00. On Amazon Canada the Camco 55255 Power Grip was $87.59 plus $26 shipping IN CANADA! :E

A friend in the park here has a relative flying down in a couple of weeks from Montreal. However I am NOT going to pay that kind of $$$ I am waiting to hear back from a Canadian RV shop, but she leaving for a few weeks. If the plug goes up in smoke I will have to do something. Need the AC here in the 30+C temps.

Here is the problem; The 50 Amp plug on the shore power cord AND the receptacle on the 50-30 amp dog bone adaptor are hot when running the air. The plug on the 50 A cord is showing signs of extended heating--rubber pulled away slightly from the metal prongs on both hots and the neutral. The U ground is OK. The 50A cord is hot only for the foot or two nearest the plug. With the AC running the plug reaches 100F, the 50A cord a foot away is 82 or so and several feet further is at 77 which at the moment is ambient. All cords and plugs are in the shade of a high brick building and never see the sun.

I tried cleaning the plug contacts to shinny brass and using a brand new dog bone adaptor with little change.

What I want to do is cut off the male 50A plug from the cord and the 50A receptacle from the dog bone and splice the remaining part together essentially, putting a three wire 30A plug on the 4 wire 50A cord. When we get up into the USA on our way home. I'll buy a new plug and socket and wire thing back correctly. There won't be many RV parks down here with 50A outlets anyway.

So here is the question: Do I splice the red and black from the 50A to the black on the 30A OR do I just not connect the red?

I am reasonably competent electrically, having completely wired the sub panels and branch circuits for both my work shop and ham radio shack and both passed the Electrical Inspectors eyes.

I have my soldering gun and tools with me--No self respecting Ham would RV without them :B, and will solder and heat shrink the connections.
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    MrWizard wrote:
    Acorn nut

    Proper name "split bolt" aka Kernie

    I usually have a few in the electrical too bag


    Thanks, on a good day I have the bandwidth to do some serious searching and .. Figured that out,, while researching another thread, about 2 minutes ago.
  • time2roll wrote:
    Yes separate branch circuits but are they on separate MAIN breakers to spread the load across both sides of the plug?


    Hard to get into the breaker box to look, so waited to watch the ammeters when the second compressor kicked in--it doesn't do it often

    Here is what I found today, the Powerline EMS was showing 25 Amps while the Xantrex inverter was showing a 13 Amps draw. So it would seem to me that there is one on each line.
  • If that translates to 13 on one side and 12 on the other then that is as good as it gets.
  • Chris Bryant wrote:
    yes- red and black tied together, but.... that 50 amp plug is nothing special to RVs- it's a commonly used one.


    YEP and while LOWE's is not an option I assume they carry a 50A pigtail for wiring in things like 220V dryers and ranges. You might find something similar there in Mexico at somewhere that deals in appliances and even might get one from a junk yard and then with a junction box you can splice in your existing cord to the new pigtail with the newer 50A plug.

    Larry
  • LarryJM wrote:
    Chris Bryant wrote:
    yes- red and black tied together, but.... that 50 amp plug is nothing special to RVs- it's a commonly used one.


    YEP and while LOWE's is not an option I assume they carry a 50A pigtail for wiring in things like 220V dryers and ranges. You might find something similar there in Mexico at somewhere that deals in appliances and even might get one from a junk yard and then with a junction box you can splice in your existing cord to the new pigtail with the newer 50A plug.

    Larry



    Dryer cords are 30a 220v, range cords are 50a 220v. The range cord is the same plug/cord-cap as on the RV.
  • UPDATE (Late, sorry)

    Once I changed the 30/50 dogbone the heating decreased substantially do I did nothing with the 50A plug.

    Later noticed that the park's breaker box was very warm. Notified the park owner who called an electrician. A BURNT buss in the breaker box. New box, new breaker, new wires spliced in: about a foot of red #8, and about 8 inches of a green #10 or possibly 12, into the middle of the white neutral! Ground? We don't need no stinkin' ground! The earth grounds (Tiera Fisica) consists of a piece of no more than #14 from the ground terminal of each breaker boxes to a ground rod at each site. There is no ground lead back to the service entrance.

    To fool the test devices, in the box, the neutral is jumpered to the earth ground terminal. I am SO glad that I am not an Electrical Inspector, or Electrician--I wouldn't be able to sleep at night!

    The electrician told me that he has many customers where he has to return year after year to replace outlets and breaker boxes due to the high salt content and humidity of the off shore winds. Not to mention many of their appliances.
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    I have had that "Warm box" on two occasions. one just like yours.

    The other was a 50 amp box. I called .. More than once, finally got an electrician out with new breakers.. He had to wear gloves to pull the old ones out they were that hot.. Even after he got the new breakers in and hooked up and power back on they were still too hot to handle comfortablly.

    The park manager tried to claim "It's all you folks running 50 amp RV's on 30 amp sites" but

    1: I'm certified in electronics so I know better than that

    2: It was a 50 amp breaker pair and a 50 amp site.. I do not draw 30 amps at peak consumption on either leg so that simply could not be true.

    (The only time I've tripped a circuit breaker (twin 30's) on my Generator I was daisy chain feeding a 2nd RV or other "Event" ... So If I don't trip 30's on the ONANm, no way am I going to overload a 50 amp park breaker)

    He finally bowed to my superior training and experience.

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