UPDATE Splicing 30A plug to 50 amp cord

[Canadian_Rainbi]

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.

[Canadian_Rainbi]

wolfe10 wrote:

Canadian Rainbirds wrote:
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.

The above in the very first post.

That is why the short term solution (in Mexico with few RV part available) is to splice the 30 amp male (adapter) to the good wire of the 50 amp shore power cord.

Yes, preference to do the splicing in a junction box, but could also "sleeve" the splice with shrink wrap as a second choice.

This is NOT rocket science. Many of us have made hundreds of electrical splices/connections and are still alive to tell about it.

Very likely the problem is the prong to wire connection(s)in the 50 amp male end.

And, when back in the states, can just install a new 50 amp male end.

OK, a few comment to update:

I did change to a different 50--30 dogbone yesterday and after cleaning the plug terminals didn't make much difference. Last evening I changed to a shiny new dognone that I had as a spare.

Today: Similar air temps. Lowest I saw the voltage was 108, running generally about 110 to 113, drawing 16 to 17 Amps. Ha! HP just switched off: live voltage up from 113 to 119

When it started this morning both compressors were running, drawing 25 Amps. For the rest of the day just one compressor is on. I haven't been able to catch the instantaneous voltage or current on compressor start up but once this afternoon I notice that the Xantrex Prosine 2.0 went into invert mode for a couple of seconds when the heatpump started. The Xantex is good for 3 kw for 20 or 30 seconds and provides 118V. (The inverter will cut off power and switch to invert if incoming is too high or too low)

Yesterday temps on the sided of the 50A plug using the IR temp gauge was 98 to 100 deg F. A few feet away the cord was at ambient (about 78 if I recall correctly.

Today, temps were 92 and 77 This using the new dogbone.

When the day cools down this evening I'll pull the plugs and take some photos.

IF I do need to cut off the 50A plug I'll do an inline splice, similar to a linesmans splice and solder, heatshrink and tape using the cut off male 30A end and cable from the old dogbone.

I'm hoping I can get a new 50A plug brought down in a couple of weeks


Time2roll: I'm unlikely to need the heatpump for heat down here--our overnight lows are all of 66 degrees. Inside the rig it may get down to 70. I just wear jeans and perhaps a long sleeve shirt until 9 o'clock or so. :B

[wolfe10]

Canadian Rainbirds wrote:
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.

The above in the very first post.

That is why the short term solution (in Mexico with few RV part available) is to splice the 30 amp male (adapter) to the good wire of the 50 amp shore power cord.

Yes, preference to do the splicing in a junction box, but could also "sleeve" the splice with shrink wrap as a second choice.

This is NOT rocket science. Many of us have made hundreds of electrical splices/connections and are still alive to tell about it.

Very likely the problem is the prong to wire connection(s)in the 50 amp male end.

And, when back in the states, can just install a new 50 amp male end.

[time2roll]

Canadian Rainbirds wrote:

time2roll wrote:
Both L1 and L2 wires (black and red hots) to the hot side (brass side)of the 30a plug.
Then Neutral to Neutral and Ground to Ground. I think I would get a new adapter or home make an adapter over lopping off the 50a plug.

Plug may still get hot and melt. Try to reduce your load with less electric and more propane.

You may have trouble getting one and especially two #6 wires properly attached to the terminals in the plug. May need a box to reduce the wires to #10.

1) How would a new adaptor help when the problem is the 50Amp plug over heating? I would still be using the same faulty plug.

2) Drawing a MAX of 25 Amps only when the second compressor kicks in. Normal draw with the heat pump running is 18 Amps. A 50 Amp plug that overheats with a 15 amp draw has to be the problem.

The only things that run on AC other than the heatpump are the battery charger and the TV. Haven't been able to figure out how to run them from propane. 🙂 The batteries are mostly charged from the 420 watts of solar. The Xantrex charger is usually disabled.

I doubt it is the 50a plug as much as the connection to the adapter. Hence I suggest a new adapter. Maybe we need a picture but seems rare. And if you are certain the 50a plug or internal connection is at fault then by all means rip it off.

Heat pump compressor(s) used for heat uses more electric power than the propane furnace. Is the fridge and water on propane? tv and battery is nothing.

Are the two compressors balanced with one on each side of the panel in the RV?

[MrWizard]

Ok there is definitely a reading comprehension problem regarding electrical connections
RV is 50 amp
The 50 amp male has overheated where plugged into the 50 amp to 30 amp DOG BONE ADAPTER
50 shore into 50 female on the adapter is the problem, poor quality adapter

Cut off both, and he will splice 30 male from adapter ( which is good and did NOT over heat) to the 50 amp shore cord

There is NO 50 amp female shore pedestal and No problem with the 30 amp male plug
And no problem with the 30 amp shore female

[aruba5er]

All I can see is smoke and fire. Maybe ambulance, fire trucks. Insurance agents. You name it. If the Plug, (male) is getting hot, you probably got a bad Outlet (female) Trying to splice #6's into a 30 amp plug sounds like fun (four # 6 wires in a space where 3 # 10's should go. Yes, if you are working with the male end of the cord you will need to put the red and black together. If working on the female end out the cord (Receptable or oulet) then black and red must be seperated or dead short. BOOM Based on your voltage swing, you could add as much as 7 amps because of low voltage which make plugs hotter.

[wolfe10]

wa8yxm wrote:
Ok, how to do it....

NOTE: the 30 amp plug may be unable to accept the 50 amp wire and for sure will have issues with TWO of those wires under the same clamp Better to use a 30 amp male pigtail and a junction box.

Yes, I like the idea of making the 30 to 50 splice inside a junction box as well. Should be able to find that inexpensively anywhere.

[wa8yxm]

Ok, how to do it....

50 amp cord has 4 wires, typically Black, Red, White and Green

White and Green are the same as on a 30 amp plug.. So is the black
The red on the 50 is optional, some have 2 blacks, why
Well red and black connect together on the 30 amp

NOTE: the 30 amp plug may be unable to accept the 50 amp wire and for sure will have issues with TWO of those wires under the same clamp Better to use a 30 amp male pigtail and a junction box.

[Canadian_Rainbi]

pianotuna wrote:
Do not get the cameco female. Their 30 amp will burn up with a 15 amp shore power supply. I got progressive 2nd time round--not a hint of burn up.

BTW the most frequent cause of burn up is low voltage. I'm using an autoformer now and love it. Sola Basic 4000 watt. They make an 8000 watt unit too!

Thanks Don, ahead of you on this one!

Ordered one on Wednesday. Delivery one week to 10 days. Don't know what they cost at home but here run about 3,500.00 pesos. The Peso is running about 16 to the Canadian dollar. About $220.00 CDN

Voltages swings here from over 130 overnight and sometimes under 105 during heavy load periods during the day. I am on the same meter feed as the rig next door and his connectors are not heating up, except for his surge protector where the 30A female burnt up. I had a spare for him.

[Canadian_Rainbi]

time2roll wrote:
Both L1 and L2 wires (black and red hots) to the hot side (brass side)of the 30a plug.
Then Neutral to Neutral and Ground to Ground. I think I would get a new adapter or home make an adapter over lopping off the 50a plug.

Plug may still get hot and melt. Try to reduce your load with less electric and more propane.

You may have trouble getting one and especially two #6 wires properly attached to the terminals in the plug. May need a box to reduce the wires to #10.

1) How would a new adaptor help when the problem is the 50Amp plug over heating? I would still be using the same faulty plug.

2) Drawing a MAX of 25 Amps only when the second compressor kicks in. Normal draw with the heat pump running is 18 Amps. A 50 Amp plug that overheats with a 15 amp draw has to be the problem.

The only things that run on AC other than the heatpump are the battery charger and the TV. Haven't been able to figure out how to run them from propane. 🙂 The batteries are mostly charged from the 420 watts of solar. The Xantrex charger is usually disabled.

[Canadian_Rainbi]

wolfe10 wrote:
Another option if your 30 male to 50 female dog bone has a good male end:

Cut off the female end of the 30 amp cord and also the male end of the 50 amp cord. Splice the two together. No parts other than butt connectors and hopefully some shrink wrap to cover the spliced area. If no shrink wrap, find an old scrap of hose with the same ID as the OD of the 50 amp cord. Use it to cover the splices. Silicone the ends of the hose to make water resistant (would not say water tight).

And all correct answers on wiring:

30 amp black to BOTH 50 red and black
30 amp white to 50 amp white
30 amp green to 50 amp green

That is EXACTLY what I plan to do!

[MrWizard]

theoldwizard1 wrote:

Canadian Rainbirds wrote:

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?

If you splice them together, then (in theory) you could pull 100A @ 120V. Hopefully the breaker at the monument won't let that happen.

If you don't splice the 2, some of your AC circuit will be dead and your second A/C unit will not operate.

No offense intended but you don't know what you are talking about
You got this backwards

In this situation it is Wires that can carry 50 amps per leg attached to a male plug for 30 amp service
The supply circuit will never supply more than 30 amps

Electrically it's just like putting a 15 amp plug on a 10 gauge ext cord to run your box fan in the garage

This is Not dangerous,

Danger is the other way, using cord to small
Example put a 50 amp plug on a 14 gauge cord and plug into the 50 amp RV outlet
Because your shore cord burned out

[Dusty_R]

I've sliced/cut one of those cord caps open, and in my book the wire is not fastened together very well, which is probably the cause of the heat.
The electric code, NECA says, thou shall not splice cord.

Dusty

[DanNJanice]

I never quite figured out what you were trying to do.
Do you have 30A service at the pedestal and want to plug in your 50A power cord or do you have 50A service at the pedestal and want to plug in a 30A power cord?
My big concern would be why are things getting warm? Before I did any splicing/wiring I would get the meter out and make sure the pedestal voltage was holding up. I would also measure the current and make sure you are not overloading something.

[pianotuna]

The cameco male seems to work ok. I don't understand why the females are so very different. This did not happen to me just once, but rather 3 times.

[pianotuna]

Do not get the cameco female. Their 30 amp will burn up with a 15 amp shore power supply. I got progressive 2nd time round--not a hint of burn up.

BTW the most frequent cause of burn up is low voltage. I'm using an autoformer now and love it. Sola Basic 4000 watt. They make an 8000 watt unit too!