Receptacle overloaded?

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crtemp

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Wa state
I just had a customer text me this picture. He said he had an electric fireplace plugged into it. He says the nameplate on it says 120 volt 12.5 amps. It was plugged into a 15 amp receptacle on a 15 amp circuit. Any idea of why this plug melted? Just a faulty plug? He said the circuit never tripped.
 

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Little Bill

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Tennessee NEC:2017
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I just had a customer text me this picture. He said he had an electric fireplace plugged into it. He says the nameplate on it says 120 volt 12.5 amps. It was plugged into a 15 amp receptacle on a 15 amp circuit. Any idea of why this plug melted? Just a faulty plug? He said the circuit never tripped.

Probably a loose connection. Either the blade was worn or the receptacle was worn, or even both.
It could be (less likely) a loose connection at the terminal. But that usually just results in loss of power to the receptacle slots with the burning showing at the terminals.
 

Sierrasparky

Senior Member
Location
USA
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Electrician ,contractor
Probably a loose connection. Either the blade was worn or the receptacle was worn, or even both.
It could be (less likely) a loose connection at the terminal. But that usually just results in loss of power to the receptacle slots with the burning showing at the terminals.

You are forgetting it was a electric fireplace , in other words a space Heater. I see this all the time. General purpose receptacles are not intended for use for electric resistent heaters for long term use.
 

crtemp

Senior Member
Location
Wa state
You are forgetting it was a electric fireplace , in other words a space Heater. I see this all the time. General purpose receptacles are not intended for use for electric resistent heaters for long term use.

I told him to install a 20 amp receptacle in place of the 15 amp receptacle, do you think this will work for the long term?
 

Little Bill

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You are forgetting it was a electric fireplace , in other words a space Heater. I see this all the time. General purpose receptacles are not intended for use for electric resistent heaters for long term use.

I'm not forgetting anything. If the receptacle and cord cap (plug) are tight you shouldn't have a problem. I'm pretty sure I know what the heater the OP mentioned is. It is a 1500W heater that looks like either a wood stove or fireplace.

Now I will agree some of the no name .39 receptacles that you can buy are crap. But if the receptacle and plug are tight they should be able to handle a 1500W load. The heater in question has a thermostat and shouldn't run continuously. Also I will agree some of the commercial grade receps are made better than spec grade but not all are.
A 15A receptacle is rated for 20A pass through.
 

Sierrasparky

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Location
USA
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Electrician ,contractor
I told him to install a 20 amp receptacle in place of the 15 amp receptacle, do you think this will work for the long term?


I doubt it, In my experience the cord cap is also damaged. The problem lies with the fact those heaters are for supplemental heat. Not to combat the entire heat loss of a space which I will go out on a limb and say that is probably the case.
 

GoldDigger

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But using a specification grade receptacle would be an inexpensive improvement, as would changing to 20A. What would be a significant cost item for all receptacles in the house does not amount to much for one receptacle which is known to be heavily loaded.
 

ActionDave

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Durango, CO, 10 h 20 min from the winged horses.
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But using a specification grade receptacle would be an inexpensive improvement, as would changing to 20A. What would be a significant cost item for all receptacles in the house does not amount to much for one receptacle which is known to be heavily loaded.
True. The .39 cent bulk specials at the home center or supply house are junk. Full disclosure, I have them all over my house, but the highest load device that I have plugged in is a water cooler. I like cold beverages. The vacuum cleaner comes out once or twice a year.
 

hurk27

Senior Member
Probably a loose connection. Either the blade was worn or the receptacle was worn, or even both.
It could be (less likely) a loose connection at the terminal. But that usually just results in loss of power to the receptacle slots with the burning showing at the terminals.

You might be surprised that copper has one of the highest thermo-conductivities of most all metals, a loose connection at the screw or back stab can very easily cause this kind of damage long before you loose the connection at the screw, most of these I have run into are the ones advertised as being made by the Amish but in reality is nothing but a fancy wood cabinet around a 1500 watt electric space heater, which will find the weakest link in any electrical system, and yes they are advertised as to keep the main heat source from running as much but in many cases if it is located by the main thermostat it will keep the main heat source from even running which then allows this heater to run full time, as I have posted before, if I know that a certain receptacle will be used for a space heater I will make sure the wires are pigtailed and the wires to the receptacle are run around both screws like an "S" so that they also tighten as the screw is tightened, this gives allot more contact area of the connection and even with a 15 amp receptacle have never had one fail since, but I would make sure that the cord cap was also not heated to the point of discoloration as this is a sign that it also has been damaged and needs to be replaced.

Here with the cost of heating with electric over gas you will be paying a much higher electric bill than if you would use just gas, but the sellers don't tell them that part and just claim it will save them so much money which is the second most call back we get when they do get their utility bill and are shocked by the high electric part of the bill and I have to sit down with them and do the math so they can see that in no way can these heaters save them money, some went up as high as $400.00 a month over just using their gas fired furnace.
 
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infinity

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New Jersey
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You cannot use a 20 amp receptacle on a 15 amp circuit unless it's an individual branch circuit with only a single receptacle. That means that you're stuck with using a spec grade 15 amp device.
 

LEO2854

Esteemed Member
Location
Ma
I told him to install a 20 amp receptacle in place of the 15 amp receptacle, do you think this will work for the long term?
Why are you telling him to install a 20 amp receptacle?:blink:

You should go there and see what's going on, I'll bet the cord cap was not fully inserted causeing arcing and over heating.

Also is that even on a 20 circuit?
 

don_resqcapt19

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Illinois
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retired electrician
... He said the cord wasnt damaged at all though
Maybe the cord wasn't but the plug on the cord was. That black stuff on the receptacle is part of the plug...it melted.
In my opinion, this is a plug receptacle connection problem and not a wire terminal connection problem. It can be caused by either the or the receptacle, or both. There is not enough contact pressure between the plug and the receptacle and the poor contact produced excessive heat.
Install a new cord end and a spec grade receptacle.
 

norcal

Senior Member
Maybe the cord wasn't but the plug on the cord was. That black stuff on the receptacle is part of the plug...it melted.
In my opinion, this is a plug receptacle connection problem and not a wire terminal connection problem. It can be caused by either the or the receptacle, or both. There is not enough contact pressure between the plug and the receptacle and the poor contact produced excessive heat.
Install a new cord end and a spec grade receptacle.


Are there any spec grade tamper resistant receptacles?
 

Little Bill

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Tennessee NEC:2017
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Semi-Retired Electrician
Maybe the cord wasn't but the plug on the cord was. That black stuff on the receptacle is part of the plug...it melted.
In my opinion, this is a plug receptacle connection problem and not a wire terminal connection problem. It can be caused by either the or the receptacle, or both. There is not enough contact pressure between the plug and the receptacle and the poor contact produced excessive heat.
Install a new cord end and a spec grade receptacle.

I said pretty much the same in my first post.

I went back and looked at the picture. The receptacle, box, or both are not seated flush.
With that, there's also a good chance the receptacle is loose. If it is, there's also a good chance the plug cap wasn't being inserted fully causing the arcing/loose connection.

Edit: Given the receptacle is also a TR it was probably hard to insert the plug, giving it a greater chance it wasn't fully inserted!
 
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Rampage_Rick

Senior Member
This type of failure is also seen occasionally with electric vehicle chargers, which are also high-current long-duration loads. The first generation Chevy Volt EVSE (orange cord manufactured by Lear) was prone to overheating due to poor crimping of the brass prongs to the conductors.

As a result they changed the software in the car beginning in 2013 such that the car defaults to 8A charging, and 12A must be manually selected each time. They also switched suppliers; the newer black-cord EVSEs are made by Clipper Creek.

http://gm-volt.com/forum/showthread.php?19452-Burns-on-outlet-(picture)
 
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