Electrical Circuit out - tracking it down

[Winemaker]

The fact that you have regained function of the circuit after mentioning the high temperature in your first post, tells me that a neutral connection in a wire nut, is loose. Check connections in attic, if any, when it is bearable to go into attic, or connections on that circuit on your "hot" wall, (a wall that is getting a lot of sun).

Mining equipment is run on 3 phase w/ground cable, carrying 995V or 480V. These cables lie in the mine floor and are occasionally damaged, and sometimes may be in mud or water. It is/was standard practice to touch the back of a cable with the back of your hand to prevent the stray current to cause your hand to lock your grip on the cable. It was mandatory to wear gloves, but the back of the hand procedure saved me and several of my employees hundreds of times.

 

[CRLLS]

Don't remember the old guy working on electricity that always tested circuits with the back of his knuckle. Idea was that shocked muscles contract, so he wouldn't grab and grip if the circuit was live. I'm too much of a wuss for that action; so rarely do it.

My dad taught me that back in the early 60's. He was a volunteer fireman. He was taught to hold his hands palm up with his fist closed when entering a house where he couldn't see. If he hit a live wire, the electric shock would pull his arms away from the wire as opposed to closing his grip and grabbing the wire. Later on I learned that is called the "can't let go" scenario. It seems that a muscle needs to be repeatedly told to stay contracted every 30(ish) milliseconds. The brain does that automatically. So does an AC circuit that overrides any brain signal.

I knew an electrical who said he could feel 120V up to his elbow, 240V goes up to his shoulder. It would tell him what he was working with. This is not a recommendation!

 

[Chuckanut]

The fact that you have regained function of the circuit after mentioning the high temperature in your first post, tells me that a neutral connection in a wire nut, is loose. Check connections in attic, if any, when it is bearable to go into attic, or connections on that circuit on your "hot" wall, (a wall that is getting a lot of sun).

Thanks. That thought occurred to me as the timing of this problem with record levels of heat seemed like an 'interesting' coincidence. Perhaps a bit of heat caused expansion caused an almost condition to actually become a current problem.

While cursing the heat and electrical problems, I had the radio on and the news announced a few more dead bodies pulled from the Miami wreckage. That helps to put things in perspective.

 

[Chuckanut]

If it works, how do I know I fixed it?

I have started to go through the various outlets and switches on my problem circuit.

It looks like those stab connections make up the just about all of the original switches and outlets. I am giving each inserted wire a gentle push to make sure it is in all the way.

In one outlet, everything looked visually OK, but I gently gave a push to each wire to make certain it was in. One wire seemed to have a bit more give in it than the others when I pushed on it. Just a bit. It might be the problem or it might not.

So, this raises the issue: Since everything started working before I started my examination of the outlets, how do I know if that gentle push fixed the problem? It worked before, and it still works.

I am going to assume it was NOT the problem outlet and will keep looking at other switches and outlets, and I hope I find something that is obviously wrong with the wiring.

Intermittent problems are the worst.

 

[Jerry1]

Given that you had a problem and given that you have a less than desirable connection situation, I would replace all the receptacles starting with that circuit and continuing on throughout the house. Sucks, but that’s what I’d do. Then I’d get an electrician in to check the main panel to make sure all of those connections are tight.

 

[mountainsoft]

Given that you had a problem and given that you have a less than desirable connection situation, I would replace all the receptacles starting with that circuit and continuing on throughout the house. Sucks, but that’s what I’d do. Then I’d get an electrician in to check the main panel to make sure all of those connections are tight.

+1 Agreed!

Pushing a wire back in doesn't mean a good connection. Even if it works now, you don't know what kind of damage was done inside the outlet. Why did it come loose in the first place and what will prevent it from happening again?

You really should avoid the push connections entirely and use the side screw terminals.

As I mentioned earlier, it's not expensive or difficult to replace an outlet. You've already got the box open and the outlet out, so why not replace it with a new one.

 

[427Vette]

I have started to go through the various outlets and switches on my problem circuit.

It looks like those stab connections make up the just about all of the original switches and outlets. I am giving each inserted wire a gentle push to make sure it is in all the way.

In one outlet, everything looked visually OK, but I gently gave a push to each wire to make certain it was in. One wire seemed to have a bit more give in it than the others when I pushed on it. Just a bit. It might be the problem or it might not.

So, this raises the issue: Since everything started working before I started my examination of the outlets, how do I know if that gentle push fixed the problem? It worked before, and it still works.

I am going to assume it was NOT the problem outlet and will keep looking at other switches and outlets, and I hope I find something that is obviously wrong with the wiring.

Intermittent problems are the worst.

Generally when you get to the offending outlet you will know it. More than likely it has been arcing and burning for a while. Usually the back of the outlet is burned up and crusty. Sometimes the back of the outlet is melted away. Make sure to trim the burnt wire back and get to some good clean copper before you wrap it around the screw and make your new connection.

 

[calmloki]

Generally when you get to the offending outlet you will know it. More than likely it has been arcing and burning for a while. Usually the back of the outlet is burned up and crusty. Sometimes the back of the outlet is melted away. Make sure to trim the burnt wire back and get to some good clean copper before you wrap it around the screw and make your new connection.

This. Also, wiggling the wires will often cause the failure to pop up again. Agree that intermittent problems are the worst.

 

[Chuckanut]

+1 Agreed!

Pushing a wire back in doesn't mean a good connection. Even if it works now, you don't know what kind of damage was done inside the outlet. Why did it come loose in the first place and what will prevent it from happening again?

You really should avoid the push connections entirely and use the side screw terminals.

As I mentioned earlier, it's not expensive or difficult to replace an outlet. You've already got the box open and the outlet out, so why not replace it with a new one.

I have to agree with you. The more I think about it the more it seems probable that one after another of these outlets is going to fail. Sort of like the freeze plugs on a car I owned in the 80's.

I am going to try and find an electrician to replace all the outlets and switches. I might try it myself but my knees may not agree with spending that much time on the floor.

 

[freedomatlast]

OP's house was most likely all wired at one time using the same brand of outlets from the same lot. If the spring force in the poke in holes in the back of the receptacle is relaxed on one, the other's most likely also have compromised spring force and thus have the potential for a loose connections which could lead to a fire.

My recommendation is to replace all the outlets in the entire house with new ones, and use the screws for termination instead of the poke in holes. Some may say just use the existing receptacles and just move the wires to the screws, but the outlets may have already been subjected to higher temperatures due to loose connections, so I wouldn't take the chance. Also, when you have the outlet out of the box, and have the wires removed from the back, at that point you may as well use a brand new, brand name outlet and have piece of mind for a very minimal cost. Also, be sure to cut, strip and use fresh cut wire under the screw termination.

 

[Chuckanut]

Most of the switches and outlets in my place have NO screws. At least the ones I checked this morning.

Thankfully new ones are not expensive.

 

[travelover]

Most of the switches and outlets in my place have NO screws. At least the ones I checked this morning.

Thankfully new ones are not expensive.

Buy good ones in bulk - they are not expensive. Do a circuit at a time. Once you get a rhythm, you'll be knocking them out in a few minutes each.

 

[ls99]

Most of the switches and outlets in my place have NO screws. At least the ones I checked this morning.

Thankfully new ones are not expensive.

A wise investment and effort. Over ten years ago I got rid of all back stab wiring to Outlets and used screw connections. Originally I found an intermittent outlet, removing the socket revealed charred wiring and and outlet body. Sure beats filing a claim for burned down house.

 

[ERD50]

Buy good ones in bulk - they are not expensive. Do a circuit at a time. Once you get a rhythm, you'll be knocking them out in a few minutes each.

Yes, from the little bit I've looked into it, for just a little more you get a much better product.

My personal preference (and I'd be interested in feedback on this) is the type where you strip the wire, and place it straight under a clamp that is under the screw. It's kind of like a sandwich, the screw clamps down on the wire which is between two plates.

To me, this is much better than having to try to form the wire into just the right shaped "J", trying to wriggle it around to fit under the screw, and having to pay attention to getting it clockwise so you don't untwist it as you tighten the screw. The clamp style is so much easier, no chance of damaging/weakening the wire with a nick while shaping that "J". And no twisting around to get it to fit. I figure the less you move those wires, the better.

-ERD50

 

[ERD50]

... Once you get a rhythm, you'll be knocking them out in a few minutes each.

Hah! I just replaced a clunky/sticky old push on/off rotary dimmer with a 'modern' linear travel one. Sure, should be just a few minutes, but...

The old plastic plate was cracked (I hate plastic plates), so it's off to find a nice metal one of the right style/color, and in stock. Of course, after DW sees that, she want the other two outlets to match (one GFCI, one standard duplex tied to that GFCI). Fortunately, I planned ahead and got a style that they stock the other type of plates in also.

But while that plate was ~ 1/4" taller (nice, covers the paint lines from the old) it was also about 3/16" narrower , which showed a line. So, it's a little cleaning, sanding, plastering, sanding. Then I find matching paint, but I'm having trouble getting it to blend in. It looks good in some light, and awful in others.

I'm getting closer, feathering it out as I go. But this started about three weeks ago!

-ERD50

 

[calmloki]

Yes, from the little bit I've looked into it, for just a little more you get a much better product.

My personal preference (and I'd be interested in feedback on this) is the type where you strip the wire, and place it straight under a clamp that is under the screw. It's kind of like a sandwich, the screw clamps down on the wire which is between two plates.

To me, this is much better than having to try to form the wire into just the right shaped "J", trying to wriggle it around to fit under the screw, and having to pay attention to getting it clockwise so you don't untwist it as you tighten the screw. The clamp style is so much easier, no chance of damaging/weakening the wire with a nick while shaping that "J". And no twisting around to get it to fit. I figure the less you move those wires, the better.

-ERD50

While much easier to install the wires I find I get too enthusiastic tightening the clamping plates down, and since the plate is supported by wire on one side and (normally) nothing on the other the screw head goes down crooked and I tend to hear breaking plastic. Poorly calibrated tightening torque on my part - others probably do better.

 

[427Vette]

Yes, from the little bit I've looked into it, for just a little more you get a much better product.

My personal preference (and I'd be interested in feedback on this) is the type where you strip the wire, and place it straight under a clamp that is under the screw. It's kind of like a sandwich, the screw clamps down on the wire which is between two plates.

To me, this is much better than having to try to form the wire into just the right shaped "J", trying to wriggle it around to fit under the screw, and having to pay attention to getting it clockwise so you don't untwist it as you tighten the screw. The clamp style is so much easier, no chance of damaging/weakening the wire with a nick while shaping that "J". And no twisting around to get it to fit. I figure the less you move those wires, the better.

-ERD50

These are the best receptacles to use. They are called “ spec grade” receptacles. They still have a hole that looks similar to the backstab outlets everyone is referring to. However the hole is there to give access to the two plates that you refer to. You can absolutely tell when you have a spec grade outlet in your hands compared to residential grade outlet they are much more stout. Even the plastic somehow feels stronger and more robust. Like expected....they do cost more.

 

[CRLLS]

These are the best receptacles to use. They are called “ spec grade” receptacles. They still have a hole that looks similar to the backstab outlets everyone is referring to. However the hole is there to give access to the two plates that you refer to. You can absolutely tell when you have a spec grade outlet in your hands compared to residential grade outlet they are much more stout. Even the plastic somehow feels stronger and more robust. Like expected....they do cost more.

I want to add. I recently found on some new duplex outlets, the size of the hole on the back is now sized in order to prevent the insertion of 12Ga (20A) wiring into a 15A outlet. The last I knew, 15A outlets on 20A circuits was still allowed and common practice in residential wiring. I can't remember whether these were "back stab"" connections or the clamp style you mentioned. I'll admit it has been some time since I read the NEC on this.

 

[427Vette]

I want to add. I recently found on some new duplex outlets, the size of the hole on the back is now sized in order to prevent the insertion of 12Ga (20A) wiring into a 15A outlet. The last I knew, 15A outlets on 20A circuits was still allowed and common practice in residential wiring. I can't remember whether these were "back stab"" connections or the clamp style you mentioned. I'll admit it has been some time since I read the NEC on this.

The sizing of the backstab holes was actually a code change about 20 years ago. Ever since then the manufacturers have made the holes smaller as to not accept a 12 ga wire. The spec grade outlets that I mentioned are not a backstab outlet but rather have holes in the back to slide the wire into then tighten a screw.

 

[ncbill]

You can still "just push in the wire" with back-clamping outlets...the screw clamps down on the wire, no need to curl hot or neutral around the screw (though IIRC, you still have to do so for the ground)

When Ive replaced them with the above I've found the spring connection on back-stab outlets still holding just fine after nearly 50 years...but the plastic (outlet located above baseboard heater) itself has degenerated into crumbs.

 

[CRLLS]

The sizing of the backstab holes was actually a code change about 20 years ago. Ever since then the manufacturers have made the holes smaller as to not accept a 12 ga wire. The spec grade outlets that I mentioned are not a backstab outlet but rather have holes in the back to slide the wire into then tighten a screw.

WOW. 20 years ago huh? How time flies! I understood the clamping function. I wasn't sure if the hole size limiting feature was on both the back stab and the clamping style outlets. Thanks.

I personally never trusted the backstab versions, especially when wiring outlets in a daisy chain situation. I always tighten the screw on the wire.

 

[427Vette]

WOW. 20 years ago huh? How time flies! I understood the clamping function. I wasn't sure if the hole size limiting feature was on both the back stab and the clamping style outlets. Thanks.

I personally never trusted the backstab versions, especially when wiring outlets in a daisy chain situation. I always tighten the screw on the wire.

I just looked it up, it was the 1996 NEC code that disallowed backstabbing 12 ga wires. It was 25 years ago!

 

[YB88]

It always pays to take time to map a home's electrical system. That means figuring out which circuits have GFC outlets and which plugs go to them.

I also diagram all circuits and lights and note which circuit breaker goes to which rooms. Makes diagnosing a problem quick & efficient.

I want to reiterate this point --- I've found it to be very worth while to take the time to make a detailed map of each circuit, print that out and tape it up inside the circuit box door or nearby. I include the amperage of each circuit (though this is already findable in the box itself), and I put an asterisk by each circuit that has a GFCI outlet on it, putting the GFCI as the first item in the list of things the circuit powers --- so that it's easy to go right to the appropriate GFCI if one of them needs to be reset.


An easy way to map your circuits is with a "circuit breaker finder" --- you plug a little unit into an outlet, then run a battery powered detector along your circuit breaker to identify which circuit the outlet is on. There's a screw-in adapter for light sockets.
The other way is to somewhat tediously turn off power to a circuit and then go around trying various outlets and lights. I've found it easier to do that with two people using walkie talkies or cell phones, one at the circuit box, one roaming around the house.

A bit time consuming, but worth it. It also helps me see the sort of "gestalt" of things. Do I have a GFCI in this old house everywhere I should? Am I likely to put a heavy load on a 15 amp circuit that already has a lot of things drawing power from it? That sort of thing.

 

[Blue531]

Had an issue two years back where most of the circuits on one side of my house were not working. I live in a small house of about 1,000 Sq feet. The central air was out, too. So, one side of house had power and the other did not. Turned out there was an extra breaker box on the outside of the house which had been installed when the new central a/c was installed about 15 years ago. After a bad rainstorm, water had gotten in and damaged the breaker.

 

[ncbill]

I want to reiterate this point --- I've found it to be very worth while to take the time to make a detailed map of each circuit, print that out and tape it up inside the circuit box door or nearby. I include the amperage of each circuit (though this is already findable in the box itself), and I put an asterisk by each circuit that has a GFCI outlet on it, putting the GFCI as the first item in the list of things the circuit powers --- so that it's easy to go right to the appropriate GFCI if one of them needs to be reset.


An easy way to map your circuits is with a "circuit breaker finder" --- you plug a little unit into an outlet, then run a battery powered detector along your circuit breaker to identify which circuit the outlet is on. There's a screw-in adapter for light sockets.
The other way is to somewhat tediously turn off power to a circuit and then go around trying various outlets and lights. I've found it easier to do that with two people using walkie talkies or cell phones, one at the circuit box, one roaming around the house.

A bit time consuming, but worth it. It also helps me see the sort of "gestalt" of things. Do I have a GFCI in this old house everywhere I should? Am I likely to put a heavy load on a 15 amp circuit that already has a lot of things drawing power from it? That sort of thing.

Had to replace the original master bathroom GFCI outlet (protects 3 downstream outlets) a couple of years ago with one of the new designs with LED indicator.

Couldn't for the life of me get the new GFCI to reset...finally figured out that "load" and "line" pairs were connected backwards on the original GFCI outlet.