Recepticle melted- smoky (water heater, phone, microwave, sinks)

[VegasGrace]

I have an older home (built before cell phone chargers/laptops/microwaves/etc.) so it doesn't have many circuits...

I've mapped out everything and ensure nothing is overloaded.....except a heater, liquid filled oil radiator type.

Over the past few weeks I could swear I heard a buzz noise from the breaker box....only finding the culprit last night. The buzz lasted in time for me to get to the box to start flipping switches.
I had one of the heaters plugged into the circuit w/ the refrigerator. So I unplugged the heater and the buzz hasn't come back.

Looking at my 'map' I decided to plug in the heater to a wall recepticle that shared a circuit w/ my daughter's lcd tv, alarm clock, and bathroom recepticle.

This morning she came to wake me up due to a 'burning smell' and it was smoky.
I immediately ran around smelling recepticles and sure enough...as soon as I opened her bathroom door- grey smoke. I turned off the switch at the breaker box and unplugged the newly added heater in the living room on the same circuit.

Well, the recepticle was melted thru w/ black soot on the wall at the outlet.
Whew! The good Lord was looking after us on this one!

But now I'm stumped. I'm sure replacing the outlet w/ a new recepticle would be okay- but nothing else can go on that circuit.
But should it be a GFI plug in? It was a normal and it concerns me because I thought the breaker was supposed to flip off in this case...it didn't.
GFI? Do they 'trip' when it gets overloaded or hot?

(this summer the home is getting the electrician and baseboard heat- AND adding more circuits, of course to update the house)

[jimboburnsy]

Originally Posted by VegasGrace

I have an older home (built before cell phone chargers/laptops/microwaves/etc.) so it doesn't have many circuits...

I've mapped out everything and ensure nothing is overloaded.....except a heater, liquid filled oil radiator type.

Over the past few weeks I could swear I heard a buzz noise from the breaker box....only finding the culprit last night. The buzz lasted in time for me to get to the box to start flipping switches.
I had one of the heaters plugged into the circuit w/ the refrigerator. So I unplugged the heater and the buzz hasn't come back.

Looking at my 'map' I decided to plug in the heater to a wall recepticle that shared a circuit w/ my daughter's lcd tv, alarm clock, and bathroom recepticle.

This morning she came to wake me up due to a 'burning smell' and it was smoky.
I immediately ran around smelling recepticles and sure enough...as soon as I opened her bathroom door- grey smoke. I turned off the switch at the breaker box and unplugged the newly added heater in the living room on the same circuit.

Well, the recepticle was melted thru w/ black soot on the wall at the outlet.
Whew! The good Lord was looking after us on this one!

But now I'm stumped. I'm sure replacing the outlet w/ a new recepticle would be okay- but nothing else can go on that circuit.
But should it be a GFI plug in? It was a normal and it concerns me because I thought the breaker was supposed to flip off in this case...it didn't.
GFI? Do they 'trip' when it gets overloaded or hot?

(this summer the home is getting the electrician and baseboard heat- AND adding more circuits, of course to update the house)

Sounds like the factory-installed smoke may have been released from your wiring. You probably want an electrician to take a gander at the wires before you turn the breaker back on and I think you should probably mothball that heater. You may have compromised insulation and could be at serious risk of a fire. I would not assume that replacing the outlet is fine.

If the breaker isn't sized properly to the wiring in the walls, it wouldn't really matter how hot the wires get - the breaker would just let it happen. If the previous owners were getting a lot of "nuisance trips" they may have replaced the breaker with the next size up. It sounds like a great idea but it is actually very dangerous.

Another possibility is that the outlet that melted was a 15A and the circuit is 20A. If you had a 20A receptacle (the ones with the horizontal notch) that may not have happened.

Yet another possibility is that the terminals in that receptacle pitted and loosened over the years and putting the extra load of the heater downstream caused arcing.

In any case, you probably want a professional opinion sooner rather than later. I love to do electrical work in my house, but this would definitely be something I would call in a sparky for... And I would have done it yesterday.

EDIT: Regarding GFCI - I am guessing that this house is not grounded (all of your outlets are 2-prong, right?) in which case it would probably be smart to install GFCI protection on general principle. GFCI does not work the same way as a circuit breaker. Circuit breakers moniter current and if the pass-thru amperage gets too high they break the circuit. GFCI moniters the balance of the current between the hot and neutral feeds. There are not many good reasons for a properly working household appliance to have anything other than the same current coming out as is going in, so if the GFCI "sees" an imbalance of about 5mA it assumes that a human is receiving an electric shock (completing a ground fault) and breaks the circuit. GFCI may or may not have done anything to prevent this little mishap. It just depends on what sort of problem caused the melted outlet.

Ask your electrician to tell you about AFCI (Arc Fault Circuit Interrupt).

[VegasGrace]

Thanks for your thoughts.

After pulling out the melted receptacle, I saw it wasn't wired correctly.

Cleaned up the mess and installed a new one- it's working just fine....but I do go check it every so often to see if there are any problems.

[M3 Mitch]

Assuming you have 12 gauge wire to that recepticle, a 20-A recepticle is better for small heaters, I think what happened to you is a cheap recepticle had a high-enough resistance connection to the plug of the heater, causing more of the Joule heating to happen in the recepticle, where it melted things.

You may want to check other recepticles in the house, you probably didn't find the only bad one.

If you are not comfortable doing this work, having an electrician change out several recepticles in one visit would be more cost-effective than doing only 1 or 2. In any case this would be cheaper than a fire.

[desertsun41]

If you have a very old house you probabaly only have 16ga wire throughout. Todays code calls for 14ga throughout and 12ga in the kitchen and/or dedicated appliance lines such as the W/D. Code requires 15A outlets throughout and 20A in the kitchen. The higher the gauge the thinner the wire.

Code dictates GFIs must be installed within 6' of all water use such as sinks, tubs and W/Ds. GFIs only detect current escape and shut down. They do not protect against high amperage use. A GFI breaker can be put in the service panel which will protect every outlet on that line rather then the GFI outlets in scattered places.

If a breaker trips, you dont fix the problem by putting in a larger breaker. The whole link is only as capable of carrying current as it's weakest link. In your case the weak link is likely undersized 16ga wire. To add more insult, if you home is that old it may have aluminum wire rather then copper. Aluminim is a poor conductor of electricity and is not able to handle the loads of todays appliances. Remember most appliances are run in short spurts. Microwaves, washing machines, ovens ect..... not giving enough time to heat up undersized wire. A space heater runs for hours and hours till you run it off. That gives ample time to heat up the wire and the outlet. Once that wire gets hot enough to melt it's insulation, or paper insulation if it's old enough, you have trouble.

Those space heaters all draw some heavy amps. Hardly a day goes by in the winter when you dont see on the news about a home burning down due to a space heater. DO NOT ever leave these things on when not home. Especially if there are pets. Pets can stand the cold.

[M3 Mitch]

Originally Posted by desertsun41

If you have a very old house you probabaly only have 16ga wire throughout. Todays code calls for 14ga throughout and 12ga in the kitchen and/or dedicated appliance lines such as the W/D. Code requires 15A outlets throughout and 20A in the kitchen. The higher the gauge the thinner the wire.

Code dictates GFIs must be installed within 6' of all water use such as sinks, tubs and W/Ds. GFIs only detect current escape and shut down. They do not protect against high amperage use. A GFI breaker can be put in the service panel which will protect every outlet on that line rather then the GFI outlets in scattered places.

If a breaker trips, you dont fix the problem by putting in a larger breaker. The whole link is only as capable of carrying current as it's weakest link. In your case the weak link is likely undersized 16ga wire. To add more insult, if you home is that old it may have aluminum wire rather then copper. Aluminim is a poor conductor of electricity and is not able to handle the loads of todays appliances. Remember most appliances are run in short spurts. Microwaves, washing machines, ovens ect..... not giving enough time to heat up undersized wire. A space heater runs for hours and hours till you run it off. That gives ample time to heat up the wire and the outlet. Once that wire gets hot enough to melt it's insulation, or paper insulation if it's old enough, you have trouble.

Those space heaters all draw some heavy amps. Hardly a day goes by in the winter when you dont see on the news about a home burning down due to a space heater. DO NOT ever leave these things on when not home. Especially if there are pets. Pets can stand the cold.

Thanks for this information. I guess it depends on what the OP means by "old". Our house is from about 1950, and has 12-gauge wiring throughout, except of course the heavier circuits to the water heater (10 ga) and the range (not certain the gauge, but it appears "adequate" and of course the dryer (ditto).

IIRC, 16 gauge wire is not considered to have 15-A worth of "ampacity", and if the house has this, you should swear off any sort of plug-in heater, IMHO. Maybe run some additional 12-gauge wire to some new recepticles...depending on what kind of fuse box/breaker box you have...you can use as many cell phone chargers as you want though, these draw only very small current. Look at your TV, etc. most appliances have the amp draw listed on the label.

How many amps is 16 gauge wire good for? 10 amps if I can believe Wikipedia...this is potentially dangerous because the standard 110-V cord for household appliances is standardized for 15 amps...

This does not have to be dangerous, you as a homeowner just need to pay attention to not going over 10 amps per socket...

[VegasGrace]

My home is '67 and wired w/ heavy gage.... a contractor I had here for some work was amazed and the quality of the wiring....said they don't put stuff like that in homes anymore. I think I have 10 and 12 gage wires, is what he said.

The receptacle was simply put in wrong....the black and whites were put UNDER the screw plate...and not wrapped around the screw ON TOP of the plate. I did pull out all the receptacles and inspected them...they are fine.

My home is so old it's got alot of daisy chains. And I had put the heater on the end of a daisy chain and of course the bathroom was the first daisy...so with the wires next to plastic- it melted, of course.

Thanks for all yoru help everyone! In a few months I'm having the electrical all redone...by a certified electrician and an inspector afterwards.

[desertsun41]

Originally Posted by VegasGrace

My home is '67 and wired w/ heavy gage.... a contractor I had here for some work was amazed and the quality of the wiring....said they don't put stuff like that in homes anymore. I think I have 10 and 12 gage wires, is what he said.

The receptacle was simply put in wrong....the black and whites were put UNDER the screw plate...and not wrapped around the screw ON TOP of the plate. I did pull out all the receptacles and inspected them...they are fine.

My home is so old it's got alot of daisy chains. And I had put the heater on the end of a daisy chain and of course the bathroom was the first daisy...so with the wires next to plastic- it melted, of course.

Thanks for all yoru help everyone! In a few months I'm having the electrical all redone...by a certified electrician and an inspector afterwards.

I can assure you, I will bet the whole farm that putting the wires under rather then around the mounting screw makes no difference in the world. Nor does it make any difference if you put the wire around the screw rather then putting it in the compression hole. I also doubt anyone wired a whole house in 10ga. It would be way too difficult to pull it through the walls in addition too hard to bend it around the mounting screw of outlets...which may be why they put it under rather then around.

[jimboburnsy]

I guess electrical fires aren't that big of a deal. Carry on.

Desertsun is right - the condition you described should not have an impact. If I were a betting man I would bet that some combination of the outlet being insufficient for the pass-thru current of the heater and/or arcing created unusually high temperatures. Ignore it if you like, but you dodged a bullet.

[Bydand]

Originally Posted by VegasGrace

My home is '67 and wired w/ heavy gage.... a contractor I had here for some work was amazed and the quality of the wiring....said they don't put stuff like that in homes anymore. I think I have 10 and 12 gage wires, is what he said.

Unless the contractor was an Electrician he was probably wrong in saying 10 and 12 gauge. It is most likely 12 and 14 gauge wire (which is still the most common size's used in houses). He was right in saying we don't put stuff like that in anymore... thank God! We use better materials now than 40+ years ago.

As for older homes having 16 gauge wire in them, after being an Electrician for 28+ years, I can truthfully say that in the thousands and thousands of homes/businesses I have been in and worked on, I have NEVER seen 16 gauge wire used to feed circuits. At least not that was installed when it was built or wired. Have seen 16 gauge lampcord used to "add" a receptacle once or twice, then called us in when it failed or melted.

The receptacle was simply put in wrong....the black and whites were put UNDER the screw plate...and not wrapped around the screw ON TOP of the plate. I did pull out all the receptacles and inspected them...they are fine.

Won't make a difference 99.9% of the time. Some brands of receptacle are designed so that the wire goes under the plate and not on top. Most likely it loosened up over the years and that caused your problem, not how it was attached to the receptacle.

My home is so old it's got alot of daisy chains. And I had put the heater on the end of a daisy chain and of course the bathroom was the first daisy...so with the wires next to plastic- it melted, of course.

Not how it works at all. something was loose and caused the heating, NOT being the first on the circuit.

Thanks for all yoru help everyone! In a few months I'm having the electrical all redone...by a certified electrician and an inspector afterwards.

I highly suggest you bite the bullet right NOW for the cost of a service call and get someone to look at the situation ASAP. Don't have to rewire the house right now, but you do have a problem that should be looked at by somebody who doesn't need to get on an online forum to diagnose what is going on.