What causes a wall outlet in your house......

[Grdpa's 50 Dodge]

.....To decide to pop and bang loudly, sparks rolling, flash that darn near blinds you for a few seconds when you plug anything into it.  Last  thing was a vacuum cleaner that was off.  Tried couple other things to be sure it wasnt the item.  All the same, even when it wakes the dead loud smoke rolls and fire flies it never trips the breaker (and the breaker and box are nearly new installs).

 

  Never fear it is getting a new plug to see if that helps.  Just wondering how that can happen?

[Merle Coggins]

I’d be killing the power to it until it can be investigated thouroughly, and repaired. Don’t need I starting the house on fire. 

[1950 Special Deluxe]

My thought would be a loose connection on the plug, possibly “quick wired”.

         -wires just stuck into the back of the plug, not stripped and wrapped around the screws.

                  -wires should be wrapped around the screws clockwise so they get tighter when you tighten the screw.

When you plug something in, the loose connection sparks but never overloads the circuit to trip the breaker.

Picture from my Sister in Law’s house.

Edited January 9, 2019 by 1950 Special Deluxe
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[Dodgeb4ya]

I'd first plug in a high load item like a toaster oven set on bake to be sure its the duplex receptacle that's the problem...

If the receptacle is good it should not stop smoking for at least 15 minutes.

[Todd B]

I was remodeling a house once where I tried to arc the wires and pop the breaker for the dishwasher.  Kept on arcing and it wouldn’t pop the breaker. Pulled the 200 amp panel cover and the “Electrician” wired the 12 gauge wire to the top lugs were the power comes in.  

 

“Never assume”. 

[DonaldSmith]

"Plug"? You mean "receptacle"?  As a kid we called it the "plugger-hole". 

 

"Never assume"! 

[Dodgeed]

Just happened to me on a brand new construction apartment I had built over a new garage. It behaved like you are describing. Turns out the breaker was bad. The electrician switched out the breaker and all's good. ?

[Plymouthy Adams]

On ‎1‎/‎8‎/‎2019 at 9:06 PM, 1950 Special Deluxe said:

My thought would be a loose connection on the plug, possibly “quick wired”.

         -wires just stuck into the back of the plug, not stripped and wrapped around the screws.

                  -wires should be wrapped around the screws clockwise so they get tighter when you tighten the screw.

When you plug something in, the loose connection sparks but never overloads the circuit to trip the breaker.

Picture from my Sister in Law’s house.

 

where be the ground wire?     how old is the wiring and is the area one that stays damp?  that is a pretty crusty ground lug 

[Young Ed]

42 minutes ago, Plymouthy Adams said:

 

where be the ground wire?     how old is the wiring and is the area one that stays damp?  that is a pretty crusty ground lug 

looks like it might be on old one that grounds through the box. that's how my house and my last house both operated. I add ground wires to the box to improve the connections but it still goes back through the box

[1950 Special Deluxe]

Ground was not attached, it did ground thru the box.

It was in a basement Rumpus Room, moisture was not an issue.

As per code the ground should have been attached.

What happened in this case, was that the previous owner had added some receptacles (plugs) in the area and fished a 3rd wire into the box.

1 of the screws (both hot and neutral) had been loosened and then a 2nd wire added to each of them.

When the screw was tightened, the 1st wire was squeezed out and over time with the heating and cooling of the copper conductor from loads being turned on and off the wire was making contact and after getting hot the copper wire  would "flow" away from the screw. After cooling off it would make contact again.

It would have then got progressively worse.

[Young Ed]

4 minutes ago, 1950 Special Deluxe said:

Ground was not attached, it did ground thru the box.

It was in a basement Rumpus Room, moisture was not an issue.

As per code the ground should have been attached.

What happened in this case, was that the previous owner had added some receptacles (plugs) in the area and fished a 3rd wire into the box.

1 of the screws (both hot and neutral) had been loosened and then a 2nd wire added to each of them.

When the screw was tightened, the 1st wire was squeezed out and over time with the heating and cooling of the copper conductor from loads being turned on and off the wire was making contact and after getting hot the copper wire  would "flow" away from the screw. After cooling off it would make contact again.

It would have then got progressively worse.

wow ya only 1 wire per screw of that style. I have noticed a lot of the ones I bought for the new house have a washer with 2 little channels in it. You can install 1 or 2 wires under each screw and there is no bending of the wire. 

[Plymouthy Adams]

as per the history of my old house I live in now, was wired during the great campaign to electrify the south....circa 1930...the push was to if nothing else, get one electrical light bulb per home.  The town sprung up as a railroad town, drawing the people closer to the track from the original town some 1 mile further out.  The story was the house was wired by the railroad workers in their spare time and probably at the expense of the rail road all truth known.  When I bought this place in 1994 I discover some of the original wiring, still hot, insulation gone, glass insulators in use and immediately rewired the entire house.   No third ground back in them days, metal utility boxes everywhere...fuse box wired at 3+ times its original rating, list goes on.  County agent did not like the idea of me doing my own work but did sign off on it.   

[pflaming]

So that's what might have been the cause of my shop fire! 

[Plymouthy Adams]

you told me you were welding and grinding in the shop that morning with a can of oily rags nearby, went to house for coffee, returned to a burning shop......and that the fire marshal concluded the origin of fire to be the can of rags...…so we have a errant cat, poor shop hygiene and practices or now a faulty outlet.....

[DJ194950]

5 hours ago, pflaming said:

So that's what might have been the cause of my shop fire! 

 

Did you wire the garage or add new wires to existing wiring?

 

Did the cat do some of the work?

 

DJ

[Todd B]

Plymouthy is describing knob and tube wiring. There never was insulation on the wire just the porcelain insulators were used. I see it on most older remodeling jobs I do.  Many still in use today. 

[linus6948]

Another important factor is the receptacle itself, I saw all the scenarios already mentioned and saw a bunch that were wired correctly but where the 35 cent "builders-grade" receptacle finally failed. Unfortunately most people have no idea what is behind their receptacle cover and don`t give it a thought.

 

https://www.thespruce.com/cheap-outlets-vs-receptacles-1152790

[Brent B3B]

I work in the rental industry, it is amazing how many people over load an outlet.

doing an inspection recently, one tenant had the beloved power strip plugged in. on the other end they had a; t.v.,fan,small refrigerator, a sewing machine and a microwave.... 

And that was one outlet in the bedroom. 

On the plus side, this resident had working smoke alarms at the time.

 

not sure why outlets fail. ?

[1950 Special Deluxe]

Another scenario is, in Canada during the late 60's to early 70's houses were wired with aluminum wire because of the high cost of copper.

During various reno's people change receptacles.

The cost of a receptacle rated for aluminum wire is 3 to 4 times the cost.

They appear the same.

But, over time the aluminum "flows" away from the screw.

[Frank Elder]

2 hours ago, 1950 Special Deluxe said:

Another scenario is, in Canada during the late 60's to early 70's houses were wired with aluminum wire because of the high cost of copper.

During various reno's people change receptacles.

The cost of a receptacle rated for aluminum wire is 3 to 4 times the cost.

They appear the same.

But, over time the aluminum "flows" away from the screw.

Also factor in Dissimilar Metal Corrosion or Galvanic Corrosion where 2 different metals are in contact with each other and the weaker or less noble metal gets eaten away by the other metal. Causing separation or deep pitting in the wire.

I think what we have really learned with aluminum wiring it simply can't take the heat that copper can....

[DonaldSmith]

My son had a house with electric wiring.  We corrected several outlets by splicing short lengihs of insulated copper wire to the bare ends of the aluminum wire, using special wire nuts with sealant to prevent oxidation.  Then we connected the short copper wires to the devices.  He sold the house decades ago.  I don't think he ever checked to see if the house was still there. 

 

I understand that aluminum cable is used in high voltage distribution lines, with special connectors for sure.   Appparently aluminum domestic wiring systems were put into the market without sufficient testing.  It would not be the first such system.      

[linus6948]

Actually the service cable feeding the electric panels in most homes is aluminum wire and as long as it is sized correctly for the panel it is feeding and the exposed ends are covered with ox-guard protectant or something similar prior to being secured in the panel lugs it is just fine.

[Grdpa's 50 Dodge]

Most of our local service drops into houses etc here are still aluminum.  MOST houses dont have that for general service of outlets and switchs.  That is all copper.  All the oldest houses in town were knob and tube here.  Wire was way thinner than 14ga. but did have    some light insulation on it that is now brittle at best.

 

  UPDATE---outlet is now a pretty new one that is higher rated.  LOOKS like the hot side of the outlet was arcing to the metal box for what ever reason.  Seems winter heating , dry air in the house made it worse.  I recall last winter it did it too.  Outlet is on same wall inches from huge outlet of furnace hot air.  In old days that was only an old octopus coal, gravity only NO FAN.  It worked till it didnt and now replaced with HE gas furnace with PVC vent only.  When replacing it did turn receptacle over so black wire was on other side.  This is the ONLY metal box left in the house.  Drywall was placed OVER old plaster and lath so any old work box wont work as the screws arent long enough.  Old boxes werent next to a stud, just screwed to the lathes.  So problem all gone.  Why it only showed up while plugging into it I cant say.  Guess when I have time might run a new run of 12 gauge over there with all three wires and ground all the same size.  This one has the small ground wire yet.  The MAIN thing this run services is the 55" TV , Dish box and DVR.  Was going to take it thru that outside wall and put a GFI receptacle outside on the porch in case want to plug tools or Christmas lights outside.  

 

Dont forget to check your boxes for the Federal Pacific ones that started fires left and right and didnt pop breakers as needed.  Thats why mine is replaced!!

[Los_Control]

Loose connections is the main cause of any sparks.

Aluminum wiring inside of homes was common in the 70's, the heat and expansion contraction caused too many loose connections.

As main wiring from the service poles to the house, still used today and not a issue.

 

Anytime you get a loose connection, you going to get sparks and later fire if you get enough sparks.

If no sparks, you would get wires overheating until threw a breaker.

 

I once plugged in a 100' extension cord, tossed the end over by the tile saw. The end of the cord fell directly into a 5 gallon bucket of water ... never popped a breaker, and was a very dangerous situation if handled wrong.

I do not claim to be a expert on electricity, if you are seeing sparks there is a serious issue and usually a loose connection. What causes the loose connection can vary.

How you deal with the loose connection can save your life.

[Dodgeed]

On 1/10/2019 at 8:56 PM, Todd B said:

Plymouthy is describing knob and tube wiring. There never was insulation on the wire just the porcelain insulators were used. I see it on most older remodeling jobs I do.  Many still in use today. 

One of my rental houses has this knob & tube wiring. The house was built in 1880. Dunno when the knob & tube was added, maybe in the 1920's? But, in the older houses in this area, the knob & tube is still used, w/no problems. However, I've got the house for sale now, and the buyer had an inspection and told me he'll have the house rewired once he takes ownership.