Help on an electrical puzzle

:shock: :cool: I did a condo inspection yesterday and ran into a puzzling situation. There was a single 220v dedicated circuit near the living room window (for AC unit). There was one 20 amp breaker that was serving two circuits (wire nut connection in box, definately not the 220v outlet). The client wanted to find out which 2 circuits involved. I do not use circuit tracer. With permission, he turned off all breakers. While I used tic tracer on outlets only, client reactivated breakers. 2 bathrooms (lights and outlets) determined to be on same circuit.
Since AC outlet was 2 pole breaker, I felt that this circuit not involved. Just for fun I placed tic tracer in 220v outlet. When client turned on breaker below 220v AC, the tic tracer indicated power yet breaker was off. Did this twice-same results. When 220v AC breaker switched off, tic tracer indicated no power. Reactivated breaker below again-tic tracer indicated power. Could this be “ghosting” or an indication of wiring issue or tic tracer sensitivity?
Any help would be welcome as I am stumped.
Thanks in advance for the assist.

Very likely.

It would be somewhat normal to have an electric baseboard heater and a 240V window air conditioner receptacle powered by the same circuit in a “full” panel. This is permissible, since the heating unit and the cooling unit operate during different seasons.

Best I got…

Thanks for the reply Marc. There is no heating unit. The breaker below the 220v AC breaker was for living room outlets. Next time this happens I will check voltage.

TIC tracers are nice to determine if power MIGHT be present, but they are not a reliable indicator that power is ACTUALLY present. Consider them more of a personal safety device, and less of a troubleshooting tool, unless and until you feel comfortable interpreting the results.

It’s certainly heroic of you to attempt to provide the client with the answer to his question, but this is an effort that is probably best left to an electrician. Many people will have an electrician into their newly purchased home for something or other soon enough, so he can ask the sparky at that point if he’s still curious.

Reference this NEMA one-page bulletin on ‘Phantom Voltage’:

Somebody give this man another one of them green squares.

Very good post is a forum that needs this type of information, my hat is off to you Marc.

Very good dialog Kent and Mark

Many of the tickers today have the ability to detect induction and static voltage that will cause lights to activate BUT most with audio will not actually activate the audio ( beeping ) unless actual AC voltage is present in the repective range of the unit being used.

What type of wiring are we speaking of…BX, Romex, NMC or what have you…this could tell us something as well if using BX and using the outside case as the EGC…could be an increased G-N leakage as well…

Anyway…does the ticker you are using have the features I stated above…glows on all currents and only beeps on actual AC voltage between the spectrum of the ticker…

The best tester is a table lamp or a radio if you are working alone…


I use a Greenlee GT-11 with both light and audible alarm, do not know the specifics. Ticker lit up and beeped.


The unit was empty so no lamp available. I did have ideal multitester which I used to determine voltage (210v) but did not think to test circuit when I discovered anomoly. I thought about it when I was on the road home. I will use it next time I run into similar issue.


I read the attachment on your post and it was quite helpful. I explained to my client (in my limited way) that it was possible that the tic tracer was not providing accurate info. as it could be sensing current form an adjacent source.

Thanks again for the input.

Good old fashioned voltage meters work every time.

Hi kent…Since both sets of breakers control conductors running to the L/R is it possible that the 110v conductor is passing through the same box causing your induction tester or tic tracer to pick up a signal?


I suppose so. Next time I’ll remember to meter it to be sure. I also just switched tic tracers from sperry to greenlee and maybe the greenlee is more sensitive.

Very sensitive…

Yes, they are very sensitive. Matter of fact, I used one once and called it a piece of crap. It started to cry right there in my hands… that’s how sensitive it is. Be careful about that, unless you have tissues.