Sparking Receptacle

[jeff43222]

I installed a new circuit and receptacle yesterday for a 30A dryer. NM from the panel, sleeved with EMT on the wall, receptacle in a 1900 box. I also installed a new cord-n-plug on the brand-new dryer. I plugged it all in and tested it before I left, and everything was fine.

Last night the HO left me a message that said there had been sparks coming from the receptacle. He said the sparks were coming from the slots, but it only happened intermittently. The dryer continued to work, and the QO breaker didn't trip. I had him start it up again while I was on the phone with him last night, and he said it was working fine.

I've never encountered this before and am at a loss as to why it's happening. If it helps, it's a P&S receptacle and an Ace Hardware cord-n-plug. I use P&S most of the time, but the Ace cord-n-plug is not one I've used before (HO bought it).

[iwire]

Keeping in mind 'sparks' could be quite a range of intensity the first thing that comes to mind is a neutral to bond connection.

Is it possible that the neutral and EGC are still bonded together in the appliance?

If so a small spark might be seen when inserting the plug into the outlet.

Other than that perhaps a defective outlet.

Please let us know what you find.

[bill addiss]

I'd ask them if the plug was inserted all the way into the outlet when it happens. I can't see the slots on my dryer outlet without pulling the plug out part way.

Bill

[jeff43222]

It don't think it could be a N-G bond inside the appliance. First thing I did when I installed the cord was to remove the bonding strap. I also don't think it was a spark from inserting the plug. I inserted it myself and left it that way, and I can't think of a reason they would have pulled it out (then again, maybe they did). I did ask him if the plug was in all the way. The receptacle itself was pretty tight; I really had to push the plug into it. So I doubt the sparks are from a loose connection.

The only thing that comes to mind is maybe there's some residue (oil, metal shavings, etc.) left over from the manufacturing process. I suppose it could also be a defective receptacle.

Since the HO was unable to duplicate the problem, I told him to watch it and let me know if it happens again. If it does, I'll go out and investigate.

[LarryFine]

My first guess: one of the screw-down lugs is loose.

[jeff43222]

That would be a good guess, but I'm pretty careful about tightness.

I haven't heard back from the HO, so my guess at this point is that someone may have pulled out the plug and didn't put it back in all the way when they ran the dryer.

[TAZMAN]

Is it possible that the h.o. tryed to unplug the dryer while it was running and seen a spark as he was unplugging it.

[kbsparky]

That would be a good guess, but I'm pretty careful about tightness....

We had one instance where the threads on the setscrew in the lug were bungered. It was "tight" as far as the screwdriver was concerned, but "loose" as far as the actual electrical connection. Bad receptacle, we had to replace it.

We had the same problem with some GE main breakers a few years back when they failed to properly tap the threads on the back of the lug assemblies. Got a lot of burn outs from that episode ....

[mdshunk]

I noticed that the original poster said it was a P&S receptacle. P&S is "my brand", but I quit using their surface range and dryer receptacles (and switched to Cooper). Reason is, when you slide the front cover on, the contacts are to slide into recesses in the cover. At times, one blade of the [double wiper] contacts will slip outside of the recess in the front cover, and you can't really tell that for sure. The recess in the cover that the wipers slide into have as much to do with the pressure on the cord cap as anything. If one blade slips out of the recess when you're sliding the cover on, one of the hot legs might only have one loose wiper contacting the blade on the plug cap.

Sorry so long and confusing, but that's the best way I can relate what I've observed.

[jeff43222]

The P&S receptacle in question is not the surface-style one. It's recessed in a 1900 box. I've also use their surface range receptacles, but I haven't had problems with them.

I suppose someone may have yanked on it while it was running. That would definitely cause sparks to come out of the slots.

I don't think it's loose lugs. The wires were pretty tight after I screwed them down. Also, loose lugs would cause the sparking to be inside the box rather than in the slots, right?

So far I haven't heard back from the HO, so I'm assuming all is well. I'll call them back on Monday and make sure there haven't been any repeat episodes.

[DaveTap]

P+S? They're the ones that have the terminal surrounded by a clamp that is essentially a short piece of brass tubing that has slotted set screw threaded into the side... My guess is the "clamp" broke and the wire is now floating around inside the terminal. I see it all the time. ;)

[GUNNING]

A 1900 box? That's not a lot of room for a large frame appliance receptacle. I think the screw on the back of the receptacle let loose when you put it in the box and is arcing around either in the connection or neutral to ground. It also might be the homeowner did his own inspection and replugged in the dryer when it was on. I had a customer handyman wrap his paw around a range receptacle and complained it shocked him. He was lucky. Maybe that homeowner you haven't heard from wasn't so lucky and is still standing there with a grimace inspecting that dryer with one hand on the appliance and one on the washer.

[ritelec]

hey....maybe the ho hasen't called cause they're getting in touch with the bbb and their lawyer.........................just kiddin.....

[GUNNING]

I hate it when the BBB calls. They always want money for a bogus service. As for the lawyer, here, you are only liable for the maximum amount of profit you made. How much profit can you make on a dryer outlet?

[jeff43222]

How much profit can you make on a dryer outlet?
I made made just over five figures on that job. Unfortunately, two of those figures were after the decimal point... :D

[busman]

A 1900 box? That's not a lot of room for a large frame appliance receptacle.

A regular 1900 with flush cover - crowded. A 1900 deep with an RS cover - plenly of space. Depends on the box, the cover, the cable clamps and the receptacle.

Mark

[jeff43222]

This was a deep 1900 box -- 2 1/8" deep. I also used a surface-mount cover, which added a bit of space. I sleeved the NM into the box with EMT, so the locknut takes up some space inside. Overall, I don't think space was a problem. I hate overcrowded boxes and don't like to bother with box-fill calcs, so I just size boxes based on what will give me plenty of room.

I talked to the HO this morning, and he said there haven't been any recurrences. I also have the inspector scheduled to look at it today.

[mdshunk]

This was a deep 1900 box -- 2 1/8" deep. I also used a surface-mount cover, which added a bit of space. I sleeved the NM into the box with EMT, so the locknut takes up some space inside.

Just curious here... why didn't you use a surface dryer receptacle? Your method seems like a darned expensive way to do a surface dryer rec. Perhaps that's all you had handy on the truck that day? You can still run EMT into a surface dryer rec. I do all the time. Half inch and 3/4".

[jeff43222]

Are you talking about one of those brown, plastic "tombstone" receptacles? If so, I usually only use them for floor mountings. I've seen them on a cinder block basement wall, but they always looked kinda DIYish to me. I don't see how I'd save much time using one. I used an offset fitting from the EMT to the 1900 box, but otherwise it's the same number of parts. I was able to do the whole job, start to finish, in an hour and a half. Material-wise, I think it would be about the same money, too. Rather than a 1900 box, offset fitting, and recessed receptacle, I'd have a surface dryer receptacle. The expensive part was the 10-3 NM.

[mdshunk]

I used an offset fitting from the EMT to the 1900 box, .Now I'm super confused. You didn't bend an offset? You used some sort of fitting? That expensive dryer receptacle just got more expensive. Perhaps you are unaware that a surface dryer receptacle is the same price as a flush dryer receptacle, without the 4 square, RS cover, and offset fitting that you also used? Naturally, it doesn't matter a hill of beans to me how you did it. It just puzzles me that you did it such an expensive way is all. It's interesting to learn how other people do things.

[jeff43222]

Sometimes I bend, but I happened to have some extra offset fittings, so I used one. Taking time into account, it would have been more expensive to bend than to just slap on the offset fitting. I don't like to bother with the conduit bender if I'm only going to be making one bend. As for the cost of materials, we're only talking about a difference of a few bucks.

I still prefer to use the 1900 box rather than the surface dryer receptacle. I just think it looks better in that situation.

[jem.nola]

Sorry for intruding here, but reading thru this forum, wondering why you didn't go back and investigate your work. Checking for burns, nicked wires etc., something that validates their findings. If its nothing, at least you would know by checking it over. How many times to we put clothes in the dryer to dry overnight while we go to bed? As an electrician, I feel its a duty to guarantee our work. Worse case senareo if home has a fire due to the work performed by you that couldv'e been prevented. If you're licensed (I don't know, and I'm not critizing whether you are or not) you may be held responsible. If not, the homeowner will probably be liable for not hiring a licensed electrician. I always guarantee my work that I perform so as long it is not tampered with. If I were in this situation, I would have the homeowner turn the breaker off marked dryer and to unplug the dryer completely until I can get there, even if its a couple of days before I get there. Situation probably less than hour and instead of guessing what it is, know the problem rectify it. This is only my opinion and I'm not telling anyone how to there job. sorry for butting in.

[allenwayne]

I just have to chime in on that post.Not trying to put you down or anything like that.But the dyer has an ocpd that in the event of a burnt or nicked conductor would trip out if it contacted a ground.I personally don`t like P & S devices but that is because I found them to rather cheap and break all to easily.The part of the original post that got me was that there were sparks coming from the openings in the receptacle,as stated they would not be visible if the cord cap was fully inserted.Sorry but I take what a home owners says with a grain of salt.Having spent countless hours troubleshooting problems they swore to on a stack of bibles non existent.

Getting off the dryer thing for a sec.We had numerous service calls from a home owner screaming that the smoke detectors were chirping all the time.They were changed out several times and all connections were checked and voltage checked.I went back after another call from a very irate homeowner threatining law suits and such.I walked in and as i did I did hear a beep coming from the area of a smoke leading into the master bedroom.Wow maybe this guys is right ????? NOT!!!!!!!! On a table layed a cordless phone with a low battery beeping over and over.I`m not saying don`t follow up on a call but get the facts and determine if there could be an actual danger and if there could be an actual fault.The ocpd didn`t trip and there have been no further calls from the homeowner,I would have done the same thing.Call me if it happens again and dont touch a thing.

[jem.nola]

Sorry, I didn't mean to offend anyone. Different strokes for different folks as they say.

[brian john]

Myself...I would have investigated ASAP, pull the outlet out, open the dryer and after doing a visual and checking all connection for proper installation I would perform a fall of potential test from the outlet conductor termination connect to the dryer terminal shake the plug while testing.

If there is a problem one of the three above would locate the discrepancy.

[boater bill]

FWIW

I heard on the radio this morning that a local family had a house fire last night that started at the dryer. They were OK and damage was limited because the family dog woke them up, not the smoke detectors!!