An electrical question...

[TC10284]

I might add that the outlets cooled down after the drier was not being used. Also, when about anything more than a lamp is powered on (my computer monitor, a vacuum, or something similar), on that circuit, the lights will dim either for a ms or stay dim (if something draws heavy current such as the hair drier or an iron).

I am still concerned that their may be something seriously wrong somewhere so I will most likely take some of the above advice.

 

[DrPizza]

Originally posted by: jagec

Originally posted by: DrPizza
The power loss in the wires is pretty negligible.

Well, clearly not, if the OP's outlets are getting warm

I think he's saying that since a 220V dryer will have a higher resistance for the same heat output, the resistance of the wires is less of factor, and they won't get as warm. Which is true, but if you have to rely on tricks like that to keep your outlets from overheating, clearly something is wrong and needs to be fixed.

I was just pointing out Dave's error:

15 Amps at 110Volts is a lot of heat (current) 1,500 Watt hair dryer.

That's why Europe uses 220Volts. Takes only 7,500 watts to get the same heat.

Breaker didn't trip, so as long as everything is in good shape and up to code should be fine.

What he should have said is "it only takes 7.5 Amps instead of 15, (so the wire would heat up less)" I was just hoping to see dave post "ooops."

 

[Rubycon]

Doubling the voltage halves the current if power stays the same.

Also a 1,500 watt hair dryer does not pull 15 amps. A 120V single phase 60Hz 15 ampere circuit is commonly referred as a 1.875kW load (full).

Nevertheless if an outlet feels warm with nothing plugged in you should have an electrician check the circuit. Most outlets are serial/parallel. So you can have a load downstream drawing enough to warm up the outlet upstream. Make sure all the screws are TIGHT! Avoid backwiring the sockets. Side wire and make sure the wire goes clockwise around the screw at least 270 degrees. This will close the loop made as the screw is tightened. If you have aluminum wiring you MUST make sure your sockets are rated for AL conductors.

 

[TC10284]

I'm not surprised that MS Dawn replied. hehe ^_^

So then in summary, I gather from all the replies that for the cause, it could be:
Backwiring (backstabbed wires)
Loose wires
Or just a plain over loaded circuit with a higher rated breaker than it should be (or lower rated wires than should be)

Another note: The house was constructed in the 70's.
Most of my computers in the basement are running on 15 amp breakers per outlet that are just a few years old (wiring and all). Some are connected to an original wire that used to be used for a freezer and nothing else I believe, so that should be fine. I have no noticeable problems with my computers' electrical setup.

However, I don't like the idea of running three bedrooms off three circuit breakers. I assume new homes would have a breaker for each room. Or atleast that's how I'd probably have it done.

 

[DrPizza]

Originally posted by: MS Dawn
Doubling the voltage halves the current if power stays the same.

Also a 1,500 watt hair dryer does not pull 15 amps. A 120V single phase 60Hz 15 ampere circuit is commonly referred as a 1.875kW load (full).

Yeah, I probably should have corrected the amps too. Voltage tends to vary a bit, but it's certainly not going to be 100 volts in most situations.

However, I don't like the idea of running three bedrooms off three circuit breakers. I assume new homes would have a breaker for each room. Or atleast that's how I'd probably have it done.

In the 70's, no one imagined that each bedroom was going to have half of the things people stick in them these days. I also prefer the 1 room = (at least) 1 breaker. But, my house currently has idiotic things like 1 outlet in the basement, plus 2 in the office, 1 in one bedroom and 1 in another bedroom + the porch lights are on one circuit... Still re-wiring here, but waiting for the price to drop on copper.

 

[KMurphy]

When was your house built? Does it have aluminum wire? If so, that maybe one of the issues. There is probably a poor connection in the outlets getting warm, even though there is nothing plugged into the receptacle. The outlets are daisy chained, so even though the circuits are paralleled, the last receptacle on the circuit still depends on a connection to the first receptacle on the circuit. High current loads will test these connections. Bad connections are the main reason for electrical related fires in homes. Circuit breakers will not detect an overheated connection, because the load doesn't change. The poor connection will eventually reach a runaway condition as the I^2*R heating effects continue to escalate. Aluminum wiring was really bad about this as it's more difficult to terminate properly than copper wiring.

I would recommend opening the circuit breaker, removing the outlets from the wall, disconnect the wiring and check for contamination, cleaning the wire ends, and re-terminating the wires to the outlet. Also, note if the wire is aluminum or not. If it is, I would make plans to have it replaced, or check all terminations that are in highly loaded circuits. For example anything that uses electric heat.

 

[TC10284]

This was one of the problems that was mentioned by Batti: http://www.thisoldhouse.com/toh/knowhow...rical/article/0,16417,562098-9,00.html

The outlets and light switches are backwired. We are switching them over (it'll take a while for the entire house).
One of the white wires is black around the part that went into the back of the outlet. Check this out: when we found out they were hot, the outlet I speak of above was right behnd my bed with covers against it. I'll probably move my bed out a little and they are replacing the outlet/wiring it right. Hopefully, switching the wires to the screws will help out.

But what happens if the outlets still get warm after switching to screws?

As for the above question: The house was built in '78 and there is no aluminum wiring to our knowledge.
Also, the ohm rating was 0 when testing with a multimeter (and the breaker was off) but not eveything was unplugged from the circuit (other outlets)

I'm really glad we caught this problem, especially knowing my covers were right against that outlet with the slightly singed wire. Dangerous....crazy, man =(

 

[futuristicmonkey]

What the hell? Outlets wired in series?

Forgive me if I don't understand it - but if you plugged a chain of Christmas lights and a hairdryer into outlets which are wired in series then they both must either a) be on or b) be off. There is only two ways about a series connection. Further, this would mean that the lights would be dimmed and the output of the hairdryer decreased. This is because in series, impedances (resistance in DC terms) add, yet current is the same all throughout the circuit. The lights would see the same amount of current as the hairdryer, although it would be less than what each device was designed for.

Parallel sockets are the only things that I have ever seen - and they make sense. Each outlet (or pair of sockets) has its own pair of wires running back to the breaker/panel. This means that each socket is independent of all other sockets.

The only logical ways for sockets, which are not plugged in to anything, to be warm are a) to have some kind of internal short (or low-impedance connection) across the terminals, or b) for a hot air vent to be pointed at them.

You're not aiming the hairdryer at the outlets when you feel them, are you?

 

[TC10284]

Originally posted by: futuristicmonkey

You're not aiming the hairdryer at the outlets when you feel them, are you?

Nope, she is in the next room. The outlets getting hot are in my room with nothing plugged into them. I'm confused as to the problem myself. There are no vents near the outlets.

I hope it is just that the outlets are backwired and when we switch it over, that will help a lot of it.

 

[jagec]

Originally posted by: futuristicmonkey
Forgive me if I don't understand it - but if you plugged a chain of Christmas lights and a hairdryer into outlets which are wired in series then they both must either a) be on or b) be off. There is only two ways about a series connection. Further, this would mean that the lights would be dimmed and the output of the hairdryer decreased. This is because in series, impedances (resistance in DC terms) add, yet current is the same all throughout the circuit. The lights would see the same amount of current as the hairdryer, although it would be less than what each device was designed for.

Parallel sockets are the only things that I have ever seen - and they make sense. Each outlet (or pair of sockets) has its own pair of wires running back to the breaker/panel. This means that each socket is independent of all other sockets.

Naw, MSDawn is right. I had forgotten the specifics of how outlets get wired. Series-parallel...the circuit itself is parallel, but only two wires run from the breaker box. They get attached to the first outlet on both sides, two more wires get attached to the same outlet and run to the second outlet, and so on. So, if any of the four connections to the first outlet is poor, it could be warming up when something is drawing current through later outlets.

Diagram

 

[skyking]

Originally posted by: TC10284

Originally posted by: futuristicmonkey

You're not aiming the hairdryer at the outlets when you feel them, are you?

Nope, she is in the next room. The outlets getting hot are in my room with nothing plugged into them. I'm confused as to the problem myself. There are no vents near the outlets.

I hope it is just that the outlets are backwired and when we switch it over, that will help a lot of it.

Loose connections with a high resistance are your problem, without a doubt. The outlets are daisychained, and a 15 amp breaker/14GA circuit is at the max with a typical blowdryer, even with perfect connections. Add some of those push-in style connectors <that get looser over time> and you have a recipe for what you are describing, exactly.

I would suggest replacing the outlets, all of them, and inspecting the wiring for faults. 25 years is plenty for an outlet.

 

[futuristicmonkey]

Originally posted by: jagec

Originally posted by: futuristicmonkey
Forgive me if I don't understand it - but if you plugged a chain of Christmas lights and a hairdryer into outlets which are wired in series then they both must either a) be on or b) be off. There is only two ways about a series connection. Further, this would mean that the lights would be dimmed and the output of the hairdryer decreased. This is because in series, impedances (resistance in DC terms) add, yet current is the same all throughout the circuit. The lights would see the same amount of current as the hairdryer, although it would be less than what each device was designed for.

Parallel sockets are the only things that I have ever seen - and they make sense. Each outlet (or pair of sockets) has its own pair of wires running back to the breaker/panel. This means that each socket is independent of all other sockets.

Naw, MSDawn is right. I had forgotten the specifics of how outlets get wired. Series-parallel...the circuit itself is parallel, but only two wires run from the breaker box. They get attached to the first outlet on both sides, two more wires get attached to the same outlet and run to the second outlet, and so on. So, if any of the four connections to the first outlet is poor, it could be warming up when something is drawing current through later outlets.

Diagram

Well I'll be damned.

 

[dmcowen674]

Originally posted by: DrPizza

Originally posted by: jagec

Originally posted by: DrPizza
The power loss in the wires is pretty negligible.

Well, clearly not, if the OP's outlets are getting warm

I think he's saying that since a 220V dryer will have a higher resistance for the same heat output, the resistance of the wires is less of factor, and they won't get as warm. Which is true, but if you have to rely on tricks like that to keep your outlets from overheating, clearly something is wrong and needs to be fixed.

I was just pointing out Dave's error:

15 Amps at 110Volts is a lot of heat (current) 1,500 Watt hair dryer.

That's why Europe uses 220Volts. Takes only 7,500 watts to get the same heat.

Breaker didn't trip, so as long as everything is in good shape and up to code should be fine.

What he should have said is "it only takes 7.5 Amps instead of 15, (so the wire would heat up less)" I was just hoping to see dave post "ooops."

Close enough, you knew what I meant.

 

[dmcowen674]

Originally posted by: DrPizza
Still re-wiring here, but waiting for the price to drop on copper.

Price is insane especially when there is no shortage of copper in the world.

They simple aren't mining it to drive the prices up.