three way switches wired with 14-2 causing ground fault

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Old 05-18-18, 07:56 PM
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three way switches wired with 14-2 causing ground fault

Hi all,

I have a 25 yo house and recently modified an existing 15A bathroom circuit to add a light switch near a bathtub. Since I want to be safe, I installed a GFCI breaker for this circuit. The circuit works fine, but since installing it, when I turn on hallway lights on a different 15A circuit, the AFCI/GFCI breaker trips. It's an Eaton breaker and when I reset it, I get 5 flashes on it, which indicates a ground fault. I opened up the hallway light switches and immediately can see that there is no 3-wire used between the fixtures or the switches. Since I don't want to pull new wires, is there any way I can change these connections to correct this issue? I have the feeling the answer is no, but I wanted to check. I've attached some photos to help explain what I am dealing with. I attached the wrong sketch below but the corrected on shows the connections in the two junction boxes and some voltage readings I took from all of the connections with the switches turned off. I realize the twisted white wires are neutrals, but I want sure how to refer to them versus the white wires attached to the switches.
 
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Old 05-18-18, 08:01 PM
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corrected sketch

sorry, I meant to attach this sketch.
 
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Old 05-18-18, 08:01 PM
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Welcome to the forums.

to add a light switch near a bathtub.
Make sure you can't reach it from the bathtub.

A three way circuit with two wire cables can be very confusing.
I need to study the pictures for a minute.
 
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Old 05-18-18, 08:23 PM
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As long as the switch is not over the tub the NEC is satisfied . There is no minimum distance from a tub or shower to a switch .
 
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Old 05-18-18, 08:29 PM
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The voltages really have no meaning without knowing what the cables are.

First switch - 4 cables.
Second switch - 3 cables.

Can we assume that one of these is a cable you just installed ?
If so.... it should be temporarily out of the discussion.

You have 2) three way switches. The always live should appear at one of the switches on the common switch terminal. Is that the one where you are using the push-in connection and the screw terminal ?
 
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Old 05-18-18, 08:58 PM
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A new thought...... see if the two breakers are one above the other in the panel. If yes.... you may have a multiwire branch circuit. That would mean one neutral is shared between two circuits.

You can verify this at the panel by checking if the breakers are one above the other and if they are.... does one have a red wire on it and the other a black ?

If it is a MWBC then you cannot install a GFI in the panel for it.
 
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Old 05-19-18, 08:00 AM
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Thanks for the replies. The light switch is not easily reachable from the tub, but I wanted to be sure the next home buyer didn't raise an issue with this, so I thought a GFCI breaker would be smart to do now. For the two hallway switch boxes, all of the wires are existing ones and not new. I have only been rewiring the bathroom circuit.

Pete, you are correct, the bottom terminal (one black wire on one switch and two black wires on the other) is marked common. Voltage on the single wire terminal switch is .9 and is 123 on the double-wire terminal switch with both switches off. With the lights on, both switches register 122 volts on the bottom terminals. I'm not sure why but the two black wires twisted together in switch #1 have no voltage regardless of the lights being on or off.

In the breaker box, there is no red wire and the hallway breaker is on the left side of the panel while the AFCI/GFCI bathroom breaker is lower on the right. FWIW, both the service neutral bar and the home ground wire bar have grounds and neutrals mixed together.
 

Last edited by johnkc; 05-19-18 at 08:17 AM.
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Old 05-19-18, 09:09 AM
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voltages screenshot

I hope I'm not overly complicating this, but here's a picture of the voltage measurements I took with the switches on and off. The feed from the breaker is on switch #2 and its neutral is twisted with another neutral in the box.
 
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Old 05-20-18, 06:55 PM
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Wires labeled and more troubleshooting

I labeled all of the wires on the two light switches, so maybe you can spot something questionable. I also removed the bulbs in the hallway and flipped the switch on; this did not trip the bathroom breaker, so this is definitely the issue. I still have two wires on switch #1 that I cannot identify and they have no current.

I'll try replacing the switches with new ones next in case that is the problem.
 
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Old 05-23-18, 09:41 AM
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I figured this out. The two twisted black in switch one are from the separate bathroom circuit, but in the hallway switch box. The neutrals for those are tied to the lone neutral on the hallway circuit. I guess the electrician did this to use the bathroom neutrals. I'll have to re-wire the hall lights with 14-3 so that I can separate the two circuits and provide a neutral to tie into.
 
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Old 05-23-18, 08:10 PM
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Good job. I wished I could have been of more help but that was a questionably wired system that I would have had to have been there to fix it.
 
 

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