Dogbone heat? 50A/30A

[joebedford]

Before you say anything, I'm going to buy a new dogbone today.

I moved my rig into position to get ready for our eclipse vacation. I have a 30A receptacle that I can use in this parking spot (RV is 50A). It's fairly new and only 6' 12ga from the main breaker box.

Anyway, my dogbone had a lot of corrosion on it so I cleaned it up with a wire wheel on a dremel. No copper left - just steel.

I tried it with 2 air conditioners and it got quite warm (not hot). Then with one ac and it was a little bit warm. Now with just the fridge on, it's not warm at all.

My question is this: assuming I'm drawing 20-25A for the 2 ac, should the dogbone get warm at all? What's 'normal'?

[time2roll]

joebedford wrote:
My question is this: assuming I'm drawing 20-25A for the 2 ac, should the dogbone get warm at all? What's 'normal'?

Yes running continuous at 80 percent of rating (24 amps) will get the component warm.

[joebedford]

Bill.Satellite wrote:
A "real" electrician would never wire up a 30 amp plug with 12ga wire. You could likely get away with 10 is the run from the breaker box to the outlet is not too far. If it's a long run you would need 2 8's plus a 10 for the ground.

Like I said, my mistake - it's not 12ga, it's 6 feet of 10 gauge wire.

[Bill_Satellite]

joebedford wrote:
The owner won't change the receptacle. He's a real cheap b*******.

Actually, the receptacle was installed by a real electrician about 8 years ago and has about 1 month total running time on it - maybe plugged / unplugged 20 times total. I put another receptacle on the other side of my garage for visitors about 4 years ago - maybe I'll try that one too.

Anyway, I bought a new Camco 50A/30A dogbone today. With both acs and fridge I can imagine that it's maybe slightly tiny warmish. Certainly not 'quite warm' like yesterday. Less warm than only one ac running yesterday.

I'll report again when I've tried the other receptacle. The run from the breaker box to that one is about 25 feet, not 6 like the one I'm using now.

A "real" electrician would never wire up a 30 amp plug with 12ga wire. You could likely get away with 10 is the run from the breaker box to the outlet is not too far. If it's a long run you would need 2 8's plus a 10 for the ground.

[joebedford]

Final data is in:

15A receptacle near house breaker panel with no load - 123V

15A receptacle near RV breaker panel with both acs and fridge running - 117V

50/30 dogbone in other 30A receptacle same no heating.

[joebedford]

My mistake - I should have said 10ga. Both my 30A receptacles are 10ga wire - one 6' from 30A breaker and the other about 25' from (a different) 30A breaker.

FWIW, the cables are not enclosed - they run through and along the studs in my garage.

[MrWizard]

I moved my rig into position to get ready for our eclipse vacation. I have a 30A receptacle that I can use in this parking spot (RV is 50A). It's fairly new and only 6' 12ga from the main breaker box.

12ga is too small for 30amp circuit, too small for 25 amps

12ga is rated at 20amps to not get hot
in open air wiring, it might carry 40-50, but it would get dangerously hot
the minimum ga for 30amps is 10ga, for a 30amp dryer plug
and 8ga or larger is better for having an RV plugged in running a/c units

the heat is coming from the plug because of the 12ga wire is getting hot
this is a fire looking to happen

or did you mean to say 12ft of 6ga wire

[joebedford]

The owner won't change the receptacle. He's a real cheap b*******.

Actually, the receptacle was installed by a real electrician about 8 years ago and has about 1 month total running time on it - maybe plugged / unplugged 20 times total. I put another receptacle on the other side of my garage for visitors about 4 years ago - maybe I'll try that one too.

Anyway, I bought a new Camco 50A/30A dogbone today. With both acs and fridge I can imagine that it's maybe slightly tiny warmish. Certainly not 'quite warm' like yesterday. Less warm than only one ac running yesterday.

I'll report again when I've tried the other receptacle. The run from the breaker box to that one is about 25 feet, not 6 like the one I'm using now.

[Old-Biscuit]

HEAT is an indication of resistance.......not good thing when it comes to electricity

New dogbone...should NOT be any heat

Still heating up...receptacle corroded/loose ----replace it

[Mandalay_Parr]

Heat is caused by poor connections.
Also by excessive current.

[MEXICOWANDERER]

Inside interior unseen corrosion. You did the right thing not wait until there was smoke

[CA_Traveler]

Good answer from BB. Check the voltage in the rig with the A/Cs running as that might be a factor especially with 12ga wire. Is the wire itself 6' long?

[BB_TX]

Likely as not the receptacle is badly worn and there is resistance between the receptacle and your plug. You have done about all you can short of having the receptacle replaced. Maybe the park will be accommodating.

30 amp receptacles and plugs will get warm when used to near rating, but should not get hot.