Questions about circuit breaker finder

[byoungblood]

Can a circuit breaker finder be used to trace wiring on a multi-wire branch circuit?

I am having a difficult time tracking down where the neutral splits between two circuits that share the neutral from the panel so I can troubleshoot a voltage drop I am experiencing on one of the circuits. I presume there is not an issue using a circuit breaker finder on the wiring itself (ie., touching it to the romex up in the attic or crawl space to identify the wiring), but will it present any issues trying to identify the separate circuits since they share a neutral? I guess I could always buy one and just return it if it doesn't work correctly for my purpose, but I'd just as soon as avoid the hassle if someone has any practical experience with one in this situation.

 

[sparky 1971]

It will identify the cable that has the hot wire the transmitter is plugged into as long as you can touch the receiver to the cable, but I think that's going to be more work than it's worth.. Why not start with the easy stuff. Shut off both breakers of the MWBC and start opening up dead boxes, starting closest to the panel. If it's romex, when you find a black, red, white, that's probably where they split. If it's in conduit, it could be any combination of colors. That's the way I would do it.

 

[byoungblood]

It will identify the cable that has the hot wire the transmitter is plugged into as long as you can touch the receiver to the cable, but I think that's going to be more work than it's worth.. Why not start with the easy stuff. Shut off both breakers of the MWBC and start opening up dead boxes, starting closest to the panel. If it's romex, when you find a black, red, white, that's probably where they split. If it's in conduit, it could be any combination of colors. That's the way I would do it.

That's what I went around doing last weekend, I checked all the receptacles in the sun room and down in my shop trying to find where the neutral junction was. Apparently whomever wired this house 30 years ago saw fit to do it in a separate junction box, probably up in the attic. I can see where all of the romex crosses over the garage and heads into the rest of the house, I just need to identify which run it is so I can follow it to the box. All of the insulation up there is blown in so the box is probably buried under some insulation, making the job even more fun.

 

[wyliesdiesels]

yeah that isnt gonna work very well.

youll have better luck with a low voltage wire toner and probe... just shut off the breaker before you connect the toner to the line

 

[CADPoint]

If you want to spend some money and have a cell phone.
https://walabot.com/
https://walabot.com/

You can retrace your weekend steps another day.

Some good Dog and Hound circuit Devices exist, and trace work both Hot and Cold on Circuits. Just be careful in front of any power!
I've found that plugging in a radio also help, you can isolate mixed circuits and the tone is noisier isolating a circuit.
This has not failed me yet Sperry Circuit Breaker Finder Tracer Kit (2 piece)

 

[sparky 1971]

That's what I went around doing last weekend, I checked all the receptacles in the sun room and down in my shop trying to find where the neutral junction was. Apparently whomever wired this house 30 years ago saw fit to do it in a separate junction box, probably up in the attic. I can see where all of the romex crosses over the garage and heads into the rest of the house, I just need to identify which run it is so I can follow it to the box. All of the insulation up there is blown in so the box is probably buried under some insulation, making the job even more fun.

If that's the case, just shut off both breakers and use an idiot stick (volt pen) to find the cable that's dead in the attic. When you find it, have someone below turn one or both of the breakers on to verify you are on the right path, if so shut them back off and start following it. I am not a believer in glow pens as test equipment, but find they can be useful in certain instances.

If the house is old enough, you may very well find that the junction is in a light fixture. A lot of homes were wired through the fixtures back in the day. It really ***** having to take down a bunch of lights, especially if ceiling fans have been installed, but a guy's gotta do what a guy's gotta do.

 

[wyliesdiesels]

If that's the case, just shut off both breakers and use an idiot stick (volt pen) to find the cable that's dead in the attic. When you find it, have someone below turn one or both of the breakers on to verify you are on the right path, if so shut them back off and start following it. I am not a believer in glow pens as test equipment, but find they can be useful in certain instances.

If the house is old enough, you may very well find that the junction is in a light fixture. A lot of homes were wired through the fixtures back in the day. It really ***** having to take down a bunch of lights, especially if ceiling fans have been installed, but a guy's gotta do what a guy's gotta do.

LoL

 

[byoungblood]

If that's the case, just shut off both breakers and use an idiot stick (volt pen) to find the cable that's dead in the attic. When you find it, have someone below turn one or both of the breakers on to verify you are on the right path, if so shut them back off and start following it. I am not a believer in glow pens as test equipment, but find they can be useful in certain instances.

If the house is old enough, you may very well find that the junction is in a light fixture. A lot of homes were wired through the fixtures back in the day. It really ***** having to take down a bunch of lights, especially if ceiling fans have been installed, but a guy's gotta do what a guy's gotta do.

1988/89 old enough to run across that kind of wiring?

I'll see if the boss will give me permission to shut the power off to her art studio/office space again.

 

[b-boy]

If you want to spend some money and have a cell phone.
https://walabot.com/
https://walabot.com/

I bought one of these. I didn't have good luck with it.

My walls are plaster and it just didn't work very well.

 

[sparky 1971]

1988/89 old enough to run across that kind of wiring?

I'll see if the boss will give me permission to shut the power off to her art studio/office space again.

It could be old enough. I started in 1994 and I've never worked anywhere it was common practice. I have a hard time seeing an attic junction box on a house that new unless it's an addition.