Electrical issue

[Jim Benante]

A few weeks ago my wife mentioned the microwave was broken. It is an above the stove unit with exhaust for the stove tops. I wasn't too upset as they aren't that expensive. Then a few days later she tells me it is working again. Then a few days later no dice again. My FIL was in town shortly thereafter and we tested things with a multimeter. We got a reading of 72-73 volts and I hooked up a circuit tester and it read a code for open neutral. We went to the panel and toghtened all the neutral connections. I then tested the other outlets on the circuit. All outlets tested out at 120V except one that wasn't being used, it read 73V. When tested from hot to ground I got 120V so again a problem with the neutral. This is where it gets weird. So we put the outlets back in the wall and whalla 120V. Microwave has power and is ready to go. My FIL was just leaving town at this point in time so he looks like the hero. Well about 30 minutes after they left it was lunch time and my wife was preparing lunch for my son. Microwave not working. A few days pass and after some nagging about getting an electrician I take another stab at it. I disassemble the two culprit outlets and reassemble. 120V on both microwave back in order. A few hours later 73 volts again at both outlets.

Can anyone tell me what to do or where my problem is. There are several other outlets on this circuit and they work just fine. I am confused and tired of this rollercoaster.

[Randy Meijer]

For a start, I'd spend 3 bucks and buy a couple of new outlets. Cut off about a half inch of the wire going to each outlet to be sure you have a fresh connection at each outlet. It's probably only the upstream outlet that is a problem; but it doesn't cost much to change out both. It is also possible that both of the 73 volt outlets are OK and the problem lies with the wire or outlet upstream of those two.

[Jim Becker]

I agree with Randy...likely a bad connection on the outlet, especially if they are "cheap, push-in, back-wired" outlets. If changing the physical outlets doesn't fix the problem...call a qualified electrician post-haste. (And don't forget to kill the breaker when you are swapping out the outlets!)

[Kent Fitzgerald]

Well, you're smarter than I am - I once replaced every receptacle and connection on a flickering circuit before I checked the neutral connection in the panel.

I agree with Randy that the problem is probably at the next upstream receptacle. If you have push-in backwired receptacles, they're almost certainly the culprit. Replace with wire nuts and pigtails.

[Lee Schierer]

I just encountered the same thing with a bathroom outlet at my son's house. Sometimes it would work and sometimes it would not,yet the circuit breaker and upstream ground fault was always on. We found the problem to be the push in wire connection on the back of the receptacle. I moved the wires to the screws and everything works fine. I hate push in wire connections.

[Jim Benante]

Thanks for the help. I will buy a few new outlets. I had kind of planned on trying that anyway.

One thing to mention is that I did these outlets about a year ago and they are the nicer looking type, but are push in. I just don;t get why after a year I am having problems all the sudden.

I'll let you know the outcome.

[Don Baer]

One thing to mention is that I did these outlets about a year ago and they are the nicer looking type, but are push in. I just don;t get why after a year I am having problems all the sudden.

The problem with the pushin type is they rely on a mechanical tension to carry current. They don't realy grip that tight and with time the spring loaded clips get weak. They are quick to use but they are not as good to use as strewing the wire in.

[Kent Fitzgerald]

No offense intended, but I've seen cases where receptacles were miswired by pushing the wire into the (rectangular) release slot, rather than the (round) terminal hole. The result is a very weak connection that will sort of work, for a while. It's a fairly easy mistake to make (and one more reason not to use push-in connnections).

[Jim Becker]

There are cheap back-wire outlets and good back-wire outlets. The difference is money and design. The better ones (which I like) are commercial grade and secure the wire with a screw...you just don't have to deal with getting the right "curve" on the wire first like you do with the normal screw terminals. And they are maybe two or three bucks more each than the cheapies...not a whole lot when you consider things.

For the record, I had a very similar problem to the OP in my previous residence in an upstairs bedroom. The builder's electrician used the cheap push-in, back-wired receptacles and after a few years a few just didn't grip the wire very well, causing really strange and intermittent problems very much like described in post one above. At that time, it took me a long time to figure things out as I was "new" to home improvement...and it was frustrating!

[Jim Benante]

I agree that the push in are not the way to go. I bought these without considering that they were pushins. I liked they way they look. They are the squared off type and are a nice clean white. They look great and I had used them in another room and a another residence without problems. Maybe I can find some heavy duties that also look nice or maybe they have this same type in a heavy duty type.

It really has to be the plugs as I was able to get it working with only messing with the plugs.

Kent-No offense taken, but I do have them wired correctly.

[Chris Padilla]

I agree with Randy...likely a bad connection on the outlet, especially if they are "cheap, push-in, back-wired" outlets. If changing the physical outlets doesn't fix the problem...call a qualified electrician post-haste. (And don't forget to kill the breaker when you are swapping out the outlets!)

I believe the correct term for the "cheap, push-in, back-wired" receptacles is back-stabbed.

The kind you want and others have referred to are called back-wired. These have a hole you insert the wire into (use the strip gauge) and then you turn a screw that literally clamps the wire in place. How hard it clamps depends on how much torque you put on the screw.

[Jim Becker]

I believe the correct term for the "cheap, push-in, back-wired" receptacles is back-stabbed.

That's why you're a REAL engineer and I'm a mere consultant...

And...I really agree with your terminology! Very true. Very true.

[Rob Russell]

I believe the correct term for the "cheap, push-in, back-wired" receptacles is back-stabbed.

The kind you want and others have referred to are called back-wired. These have a hole you insert the wire into (use the strip gauge) and then you turn a screw that literally clamps the wire in place. How hard it clamps depends on how much torque you put on the screw.

Chris,

Couldn't have said it better myself.

Rob

[Chris Padilla]

Chris,

Couldn't have said it better myself.

Rob

LOL! I was expecting yet another correction from Mr. Rob "NEC" Russell but I guess this time, I learned correctly (and most importantly, remembered correctly) and thus received, shall I say, adulation?!

[Rob Russell]

LOL! I was expecting yet another correction from Mr. Rob "NEC" Russell but I guess this time, I learned correctly (and most importantly, remembered correctly) and thus received, shall I say, adulation?!

"adulation" ... ackkkk, cough, choke ... something's stuck in my throat ... can we just go with "ya done good"?

BTW, back-stabbed vs. back-wired isn't an NEC issue, it's more of a device quality issue.