jamlove
Feb 28, 2008, 09:04 AM
Hello all,
I've run into a "situation" I'd like advice on.
The job was simply replacing an outlet. Inside the outlet box are 2 12/2 cables with ground. The outlet is a standard 110V, and the top and bottom receptacles are connected (in other words, it has not been severed to form separate-circuit outlets).
My girlfriend started this job before I got there... she turned off the breaker, tested the TOP outlet with a test light, then began removing wires - neutral wires first. And one of them shocked her! So she called me to see if I could find out why.
We shut off main power and removed the old outlet (which was damaged physically, hence the replacement). Then I used a voltmeter to determine that one of the cables was controlled by the original breaker (let's call it "A"). However, with A off, there was still 110V (relative to ground) on BOTH the white and black wires of the second cable in the box.
Only after turning off a second breaker, "B", did the voltage go away.
With A and B off, I put an ohmmeter on the neutral and hot of cable 2 and found it to be in short-circuit.
Now is where it gets funny: With A and B off, all lights and outlets in the bedrooms and living area were off. With A off, B on, but the outlet removed, PART of the bedrooms and living area were still off. Part were on. With A on and B off, the outlets and lights that were off remained off... suggesting that A does not independently control them.
The only way that everything "works" is when the outlet is reinstalled, or the neutrals and hots are connected.
But HOW?
How can there be 110V on the B neutral line (relative to ground or relative to A's neutral line)... but somehow it doesn't cause a short circuit when A and B are connected via this outlet?
I'm sorry this post may be confusing... I'm confused and I'm physically here seeing it. But any help is appreciated.
I've advised my ladyfriend to seek the help of a pro and see if things are "fine" or are potentially hazardous. We do not know if somebody has rewired this home previously, but we have not messed with any of it.
Note: this is a 1970s home and is fairly simple. There are no 3-way switches, sub-panels, etc in the house. If that helps.
Thanks again, look forward to your help.
- james
I've run into a "situation" I'd like advice on.
The job was simply replacing an outlet. Inside the outlet box are 2 12/2 cables with ground. The outlet is a standard 110V, and the top and bottom receptacles are connected (in other words, it has not been severed to form separate-circuit outlets).
My girlfriend started this job before I got there... she turned off the breaker, tested the TOP outlet with a test light, then began removing wires - neutral wires first. And one of them shocked her! So she called me to see if I could find out why.
We shut off main power and removed the old outlet (which was damaged physically, hence the replacement). Then I used a voltmeter to determine that one of the cables was controlled by the original breaker (let's call it "A"). However, with A off, there was still 110V (relative to ground) on BOTH the white and black wires of the second cable in the box.
Only after turning off a second breaker, "B", did the voltage go away.
With A and B off, I put an ohmmeter on the neutral and hot of cable 2 and found it to be in short-circuit.
Now is where it gets funny: With A and B off, all lights and outlets in the bedrooms and living area were off. With A off, B on, but the outlet removed, PART of the bedrooms and living area were still off. Part were on. With A on and B off, the outlets and lights that were off remained off... suggesting that A does not independently control them.
The only way that everything "works" is when the outlet is reinstalled, or the neutrals and hots are connected.
But HOW?
How can there be 110V on the B neutral line (relative to ground or relative to A's neutral line)... but somehow it doesn't cause a short circuit when A and B are connected via this outlet?
I'm sorry this post may be confusing... I'm confused and I'm physically here seeing it. But any help is appreciated.
I've advised my ladyfriend to seek the help of a pro and see if things are "fine" or are potentially hazardous. We do not know if somebody has rewired this home previously, but we have not messed with any of it.
Note: this is a 1970s home and is fairly simple. There are no 3-way switches, sub-panels, etc in the house. If that helps.
Thanks again, look forward to your help.
- james