Troubleshooting question

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O

olly

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Berthoud, Colorado
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Master Electrician
I have a floor outlet without power. Short of opening every lighting and outlet / switch to try to find where this might be feed from does anyone have a tool or trouble shooting technique that might save me sometime.

Thanks,

Luke
 
The first thing I do is check continuity between neutral and ground to determine if the wiring has been completely disconnected.

Next thing i would do is go to the nearest couple of receps and open them up to see if it’s piped in there.

If you know what circuit it’s supposed to be on, I would find what should be the middle of that circuit and disconnect all the wires to see if it breaks the neutral ground bond. If so, work your way back toward the Floorbox. If not, keep going the opposite direction.

I’d also look above the ceiling to see if you can spot a conduit coming up, or look in the panel to see if it’s piped in there.


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Is this residential? Or commercial? If residential, a quick thing to check would be any gfi’s tripped. If it is on a crawl space, they probably grabbed a circuit in the crawl space, which may be gfi protected. No continuity between neutral and ground is a good indicator, as gfi receptacles open both the hot and neutral.
 
And if it's commercial, use a fiberglass fish-tape to make noise in the first box the conduit hits.
 
Ideal SureTrace is a great tool for these scenarios.

I had a room go dead after a power outage, all breakers on and functional, all GFCI receps functioning, and still no power. I traced the wiring in the wall to where to signal died, went to the room on the other side of the wall, a wine cellar, and had them start taking racks down.

Found a buried GFCI receptacle back there, tripped.

$2,000 tool, 20 minutes to find the problem.
 
The junction box was in a closet ceiling. The wierd plastic cap was used instead of a wire nut and the burnt wirenut was in a crawl. These were all found with my 30 buck knock off fox and hound. Just don't run line voltage through it.
 

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letgomywago said:
The junction box was in a closet ceiling. The wierd plastic cap was used instead of a wire nut and the burnt wirenut was in a crawl. These were all found with my 30 buck knock off fox and hound. Just don't run line voltage through it.
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the $90 Fluke toner has line voltage protection(confirmed 120v) so it won't be destroyed by accidents. I've destroyed others.
 
I have an old amprobe that I have hooked a battery to and send a signal through the neutral and back on ground. unlike most tracers, this will point you toward the panelboard instead of the entire circuit.
 
TwoBlocked said:
I have an old amprobe that I have hooked a battery to and send a signal through the neutral and back on ground. unlike most tracers, this will point you toward the panelboard instead of the entire circuit.
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The Amprobe’s were bought out by Fluke I believe. I’ve had one since the late 80’s. Excellent tracer! You can reliably pull a single wire out of a bundle of 100! They are getting hard to find anymore though. The receiver sensor is bad to break loose in the nose of it if dropped.
 
hillbilly1 said:
Is this residential? Or commercial? If residential, a quick thing to check would be any gfi’s tripped. If it is on a crawl space, they probably grabbed a circuit in the crawl space, which may be gfi protected. No continuity between neutral and ground is a good indicator, as gfi receptacles open both the hot and neutral.
Click to expand...

Oh no a "GFCI" tripped !
 

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hillbilly1 said:
The Amprobe’s were bought out by Fluke I believe. I’ve had one since the late 80’s. Excellent tracer! You can reliably pull a single wire out of a bundle of 100! They are getting hard to find anymore though. The receiver sensor is bad to break loose in the nose of it if dropped.
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I've got mine in a small Pelican case marked "DO NOT BORROW." I've used the newer Amprobe and the expensive Ideal tracers, but they just don't compare. The old amprobe doesn't do dead circuit tracing, but you can create a loop with a 9 volt battery. Something I've noticed is if there is a reactive component in the circuit, like a transformer, part of the signal will be split to the reactive device even though it is not in the conventional current path to the source. It is a current tracer, and apparently when there is a phase angle, the reactive device acts as an additional current source.
 
brantmacga said:
The first thing I do is check continuity between neutral and ground to determine if the wiring has been completely disconnected.
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In case you don't know, what brant is looking for here is continuity between the neutral and the ground. I great place to start, because if there is continuity, it likely means the wiring isn't completely disconnected or cut, between the device and the power source. Nothing is a sure thing though. The wires could be cut and shorted. Just not likely.
 
Strathead said:
In case you don't know, what brant is looking for here is continuity between the neutral and the ground. I great place to start, because if there is continuity, it likely means the wiring isn't completely disconnected or cut, between the device and the power source. Nothing is a sure thing though. The wires could be cut and shorted. Just not likely.
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No continuity could also mean a tripped GFCI.
 
Little Bill said:
No continuity could also mean a tripped GFCI.
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When determining if its a gfi or afci that's stopped a 120v circuit I always check to see if the nuetral and hot are both gone and then I ask and look for someone cutting wires if that hasn't happened the chances that both hot and nuetral were lost at an outlet or junction box is low but finding a covered gfi is common.
 
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