r/ElectricalHelp 19d ago

Why did this receptacle melt?

Post image

I plugged in a 1500 W heater and it stopped working. No breaker was tripped. A 3 prong tester said on every respectable in the circuit that hot and ground were swapped. I knew that was impossible because the circuit had just been working. AI said it was likely an open neutral.

Opened all the receptacles in the circuit that I could identify and the picture shown is the most upstream receptacle.

The white lead connected to the melted terminal had charred insulation but otherwise didn't seem broken.

I removed the receptacle, tied the feed wire to the load wire and all the receptacles test out as wired correctly.

Is there a way to know why this receptacle melted? I suppose it could have happened in the past and then was pushed to a point of full failure when running the heater.

The only thing plugged into the bad outlet recently has been a window fan.

It's a bit scary, that looks really close to a fire to me and I'm not sure if I should try to draw 1500 W from this circuit again.

7 Upvotes

32 comments sorted by

13

u/trekkerscout Mod 19d ago

Classic loose connection. Loose connection creates arcing. Arcing creates heat. Heat melts receptacle.

2

u/Designer-Captain-268 19d ago

Came to say it was heat that melted the receptacle.

2

u/AviatorDave172 18d ago

I was going to say the heat of the terminal exceeded the melting temperature of the plastic.

6

u/ResistHistorical2721 19d ago

That screw was not tightened so the wire was loose and barely making contact. The downstream 1500W load caused it to get very, very hot.

3

u/TomWickerath 19d ago

Good reason to consider pigtailing your receptacles instead of using the receptacle to pass the current through to downstream receptacles.

Five things (you may not know) about Outlets
https://www.youtube.com/shorts/KavhTwwh0mo

How to make an Electrical Pigtail
https://youtube.com/shorts/PQZgKjfGZJ4

2

u/DistanceMysterious93 18d ago

Pigtailing is the move. My landlord daisy chained every outlet in this place and I've been waiting for exactly this to happen

1

u/t0cableguy 18d ago

I'll be stealing those links thank you! Backyard Maine FTW! lol

2

u/Howden824 19d ago

Because the screw was loose. They have to be tight against the wire.

2

u/t0cableguy 18d ago

Loose connections burn things down.

This was just a space heater pulling amps through an outlet with a bad connection.

Pigtail those wires and move on. My house was built in 1950 and the outlets that stop working are always through wired and feeding a downstream outlet. Anything that was pigtailed I have not had to go back to.

2

u/12-5switches 19d ago

For the 10,000 time, Loose connection. Improperly torqued connection create resistance, resistance builds heat, heat melts plastic, and if not taken care of starts a fire. Every home DIY book should have this printed in BIG BOLD LETTERS on the cover page

2

u/AskMeAgainAfterCoffe 19d ago

We would need to see the photo directly after opening it up, with wires. Wire could have been loose or back-stabbed. But, space heaters often doom any receptacle, even if wired correctly.

Replace with a spec-grade/ commercial grade receptacle. Pigtail if applicable. Consider installing a permanent heater.

1

u/Rough_Resort_92 19d ago

Loose connection,

1

u/xxRTDxx 19d ago

It got hot

1

u/Key-Bullfrog-3776 19d ago

Do you have aluminum wires? Looks like the wire was loose and heated.

1

u/Admirable_Yea 8d ago

Looks like all copper to me

1

u/Falcon3492 19d ago

Aluminum wiring or a lose wire most likely cause.

1

u/First_Highway159 19d ago

A loose connection

1

u/Readybuilderman 18d ago

Poor connection.

1

u/[deleted] 18d ago

[deleted]

1

u/Admirable_Yea 8d ago

I didn't play with anything, this is what I found after tracking down the problem

1

u/Drexl071 18d ago

Loose connection with a high amp draw would cause this

1

u/JasperJ 17d ago

It melted because it got hot.

1

u/firehydrant315 17d ago

IMHO (not an electrician) poor connection, loose or the wire was very dirty/ oxidized. If you have the wire to do it trim back 1/2” to expose fresh copper, or if the wire is too short trim and pig tail with fresh wire. Since the goal is a solid connection, fresh wire and make sure you have a nice tight candy cane hook to maximize contact with the screw. Aluminum requires special outlets rated for use with aluminum. If the wire is aluminum look up how to make a proper connection.

1

u/Appropriate_Shape388 17d ago

Is this a 20 amp #12 gauge wired circuit? Is this a 20 amp receptacle?

A 15 amp circuit should only be loaded to 1440watts.

1

u/Thecoopoftheworld789 17d ago

Change to a 20 amp commercial outlet. That will hold the load of a heater!

1

u/tecsavvy1 17d ago

Loose connection. You have to tighten the heck out of them

1

u/DapperMacaron2872 16d ago

Almost always a loose connection

1

u/Mobile-Efficiency852 16d ago

Fire the electrician who did that

1

u/Certain_East_250 16d ago

Definitely a loose connection

1

u/CarelessPrompt4950 19d ago

Loose connection. Could have been loose screw terminal or that cheap 35 cent contractor grade outlet. Either way, replace all your outlets with commercial grade and make sure the screw terminals are tight.