Howdy,

We have a fairly recently installed dryer/dryer outlet that caused the circuit breaker to trip the other day about 30 seconds into a drying cycle. Not really questioning it, I went band flipped the breaker back on. Cue electrical shorting noise, smoke, and the breaker flipping again. Pictures below are the results.





The totally fried terminal is ground. Of note, when I opened up the outlet box the ground wire that extended from the terminal to the clamp was totally detached from the ground wire continuing down the rest of the run. I imagine it melted in the "event" and caused that hole that can be seen in the clamp. Anyway, it was completely "cut" from the rest of the run and was only hanging by it's connection to the ground terminal.

Anyway, was just looking for advice on what I should do next.
-Do you guys think it's a problem with the ground for the run?
-Any ideas as to why it would have "randomly" done this? We haven't moved anything around that area recently, the terminal connections all seemed tight, and it doesn't appear that there was a mouse messing with it or anything.
-Do you think it's a problem with the dryer?

My next step was going to be to get a new outlet, cut the run back a half foot or so, install the new outlet and see if the breaker tripped again. But thought I would post here and see if I got any feedback before I try that exercise tomorrow.

Thanks in advance!

 

Looking at the one pin on the receptacle in the first pic it appears to be spread which would make for a weak connection.

Unfortunately not only are you going to have to cut the wire back and install a new receptacle but you may have to change the dryer cord if that matching prong melted in the plug.

Also check the amperage required on the nameplate.....usually just inside the door.

 

I misspoke, the terminal that is completely melted is a hot not a ground, fyi.

 

Thinking about how I confused the hot with the ground terminal caused me to go back and look at the piece of wire which "melted" off from the run inside the terminal box. I had mistaken a green section of corrosion for remnants of green shielding on the wire. Could be that the wire had been corroding near the clamp? Perhaps the corrosion is just a result of the event.

 

Sure.....a combination of a loose contact and corrosion between contacts could definitely be a problem.

 

Does the cable going to the receptacle have three insulated wires and a bare wire?There should be markings on it. What do the markings read?

 

How recent is fairly recent? Who installed the dryer outlet and circuit?

 

You may be down at home depot right now getting the parts. New receptacle and unfortunately you may need a new plug. At least clean the prongs with some steel wool. The photos are not portraying the situation the best. Would be more informative if the wire was still there. Anyhow, work carefully. I would guess loose connection or some sloppy stripping work on the hot. White to central prong. Red and black interchangale on the 2 outside prongs. Green or bare copper to the roundish prong in the middle. Make sure some of the protective outer insulation projects inside the clamp about 1/4". Tighten thge screws real good. Watch that no little bits of wire are left in the box. The 30 second delay is interesting as is the fact it was already running. I really think it was a loose wire on the burnt hot.

 

In your pictures the totally fried terminal is not the ground it is a hot. OK I see in one of your posts you realized that.

 

Yup, 3 insulated (RWB) and 1 bare ground. 10 AWG.

 

Within the past year. An electrician was not involved in installation.

 

I think Joe had the same idea I had..... that receptacle looks fairly corroded for a new installation.

Wire size is correct.

 

Final post for me. I do not like the looks of that receptacle. Looks like something you would find in a modular home. If I was doing the repair I would show up with a Leviton white 30 amp dryer recpt w/plate, a 4" square metal surface mount box w/ KOs, and a 3/8 cable connector w/ 2 screws. Mount the box with 2 screws about a foot above the dryer so it doesn't get crushed. Put a #2 staple within 12" of the box. Alternatively, if you don't use your dryer you will save a lot on your power bill.

 

Surface mount receptacles are perfectly fine to use.

 

Yup, went out to lowes this morning and got a new 30/50A 4 prong surface mount outlet. Cut the run back about 4" to expose new wire. Secured wires in the terminals and mounted the outlet up on the wall above the dryer (it was previously on the floor next to the exhaust). Cleaned up the dryer plug with steel wool, dryer plug didn't look damaged (melted) from the event. Flipped the breaker with nothing plugged in, was fine; plugged in the dryer, flipped the breaker, was fine; started the dryer and it's still running fine.

I think the conclusion that there was some corrosion on the terminals was probably what caused it to fail. Other than that I don't have any other explanation.

Thanks for all the help.

 

Yep, that's what I was thinking.

Ok, is it a 30 amp or a 50 amp receptacle, they are not the same.

 

CasualJoe, They are the same, but on 50a the neutral prong is positioned to the relative top, and the ground to the bottom. On 30a the ground prong is positioned to the relative bottom, and the ground to the top.
Sparky

Images:

30 Amp: http://bit.ly/30ADryerStraight4W
50 Amp: http://bit.ly/50AStraightBlade4W

 

I have a hard time believing a 30 amp and 50 amp receptacle would be the same in appearance and internals.

 

Hey Sparky..... your two links show two different brands of a 30 amp dryer receptacle.


I have posted a 30 amp dryer receptacle and a 50 amp range receptacle below.

 

I seem to remember ones that were able to be converted between 30 amd 50 amp configurations.

 

That would be a new on on me, but I can't remember what I had for lunch!