Smart Switches: GFCI vs. Arc Breakers?

[jgreenberg01]

Not sure where to post this, so I'll try here.

I just moved into a new home with GFCI circuit breakers. Prior to this I've always had Arc breakers and never had any problems.

All of my smart devices were moved to the new home, but two 3-way circuits are tripping the breakers. With both switches physically removed, the wire that goes to the breaker panel shows 120v on the line wire. The two traveler wires show about 40v each (should show zero, or close to it).

I've tried GE Jasco, Honeywell, and now Minoston smart switches - all of them trip the breakers. I know they were wired correctly, but I tried every iteration of wiring possible, all with the same results. Did not blow the switches in the process, they all worked as expected afterwards in other locations.

Being that this is new construction, I called in a warranty repair. The two old-school electricians that showed up knew nothing about smart switches. One of them thought that the 40v that he confirmed on the traveler wires is from "bleed from the neutral wires", also that I should replace the GFCI with an Arc breaker. Then he left.

I just ordered an Inovelli Red switch that does not require a neutral wire to see if that one works. Also the GE Aux switch that Inovelli recommends and an Aeotech Bypass in case it's required. They should all should be here in a couple of days.

Before I find - and pay - an electrician that does have knowledge of smart switches, I thought I would ask here.

Has anyone had an issue like this?

Thanks in advance!

Jeff

[Rvtravlr]

Our home has both and we’ve not had the problem you describe. We are using HSWD100+ dimmers.

[joegr]

I had a similar problem when I added GFCI to most of the circuits in my house. The stairway light is a 3-way (two switches) circuit, and turning that light on would trip one or two GFCIs. (This was before adding smart switches.) The house was originally wired using two different circuits for the stairway light. This resulted in the current from the hot of one circuit running into the neutral of a different circuit. You can't be much more against wiring code than to do that, and I'm sure it was against code back when the house was made. I did some major rewiring after that, and found plenty of other stupid things they had done.

Your GFCI is tripping because the current flowing out of the hot wire is not matching the current flowing into the neutral wire.

[TC1]

I did some major rewiring after that, and found plenty of other stupid things they had done.

Your GFCI is tripping because the current flowing out of the hot wire is not matching the current flowing into the neutral wire.

This. On both accounts. When I first moved into my house I found *plenty* of wiring practices that would make one shudder if they knew implications.

The GFCI is tripping more than likely because the neutral going to it is from another circuit, which should be definitely straightened out.

[jgreenberg01]

Thanks for the responses.

I probably should have mentioned that the dumb switches work as expected. The electrician said everything is ok because it works the way they wired it.

I know everything is not fine - this really pisses me off!

[Guest]

The two old-school electricians that showed up knew nothing about smart switches. One of them thought that the 40v that he confirmed on the traveler wires is from "bleed from the neutral wires", also that I should replace the GFCI with an Arc breaker. Then he left.

I think you need to demand new electricians. Any electrician that really knows his stuff would be concerned about the above. Having electricity "bleed" is a big warning sign.

I would demand that someone (preferably someone else) come back and fix that. Do not even mention your intention to install smart switches, since that seems to just confuse them.

Edited to add: Since this is new construction, perhaps bringing this up to the new housing (city) inspectors might be warranted.

[TC1]

Do not even mention your intention to install smart switches, since that seems to just confuse them.

Agree especially on this point. It's irrelevant to the problem on hand and will just give them excuses to invent. Bottom line is that there should be no mystery voltages on the wiring, without any devices hooked up the only potentials should be 120v (hot) and 0v (neutral).

[joegr]

There is some capacitive coupling between wires that can cause some AC voltage to show on high-impedance digital voltmeters. Connect a 100K ohm resistor between the two meter terminals to see if there is really an current sourcing ability there. If the reading goes to zero, then there is no bleed or real mystery voltage. If it remains instead, then yes, the problem is already showing.

[Dweber85rc]

it really depends on what your local codes say for what you have to use. Where I am at I believe only outlets that are outside or a wet location-i.e bathroom or kitchen- did you have to use combo gfci and arc fault breakers. Everywhere else is arc fault.

[drhtmal]

Agree especially on this point. It's irrelevant to the problem on hand and will just give them excuses to invent. Bottom line is that there should be no mystery voltages on the wiring, without any devices hooked up the only potentials should be 120v (hot) and 0v (neutral).

There is at least one instance when there could be voltage on the neutral. If a multiwire branch circuit (MBC) were installed there would be voltage on the neutral since that neutral is shared by 2 separate breakers. Here is an example https://www.twielectric.com/safety-a...ranch-circuit/ I am not saying that is your circumstance but it is worth investigation.

It is very difficult to troubleshoot these issues in a forum setting since it is hard to get an exact picture of how things are wired. Can you send some photos of the wiring at each switch?

When the sparky measured the 40v on the traveler was this when the HomeSeer dimmer was still hooked up and the power on? There is a voltage on the traveler when a HomeSeer dimmer (WD100 or WD200) or a switch (WS100 or WS200) is used with the companion switch WA100. This is by design and is how the main dimmer or switch senses that the companion switch is being used to control the dimmer or switch.

[jgreenberg01]

There is at least one instance when there could be voltage on the neutral. If a multiwire branch circuit (MBC) were installed there would be voltage on the neutral since that neutral is shared by 2 separate breakers. Here is an example https://www.twielectric.com/safety-a...ranch-circuit/ I am not saying that is your circumstance but it is worth investigation.

It is very difficult to troubleshoot these issues in a forum setting since it is hard to get an exact picture of how things are wired. Can you send some photos of the wiring at each switch?

When the sparky measured the 40v on the traveler was this when the HomeSeer dimmer was still hooked up and the power on? There is a voltage on the traveler when a HomeSeer dimmer (WD100 or WD200) or a switch (WS100 or WS200) is used with the companion switch WA100. This is by design and is how the main dimmer or switch senses that the companion switch is being used to control the dimmer or switch.

Thanks for the MBC link. The diagram shows the neutral connecting to the outlets. The neutral wires in my house all terminate at a wire nut inside the j-boxes, and are not connected to any switch terminals that I have seen in any of the j-boxes I have opened.

As far as the electric doctor's visit: I had put back the original dumb switches on that circuit before the electrician arrived - I knew that smart technology is a does-not-compute for them, plus I didn't want them to say that I voided the new home warranty by installing my own switches.

I have to install a new ceiling fan on my next day off. I'll take some pics of the wiring to post here, assuming I don't take a swan dive off the ladder. Love 12' ceilings, but not so much installing fans that high

[TC1]

I have to install a new ceiling fan on my next day off. I'll take some pics of the wiring to post here, assuming I don't take a swan dive off the ladder. Love 12' ceilings, but not so much installing fans that high

OMG... I remember those days, especially trying to do it alone. The new ceiling fans on the market are amazing with built-in install hooks and other nuances especially made for when you're doing it alone.

[George]

I think you need to demand new electricians. Any electrician that really knows his stuff would be concerned about the above. Having electricity "bleed" is a big warning sign.

I would demand that someone (preferably someone else) come back and fix that. Do not even mention your intention to install smart switches, since that seems to just confuse them.

Edited to add: Since this is new construction, perhaps bringing this up to the new housing (city) inspectors might be warranted.

Agreed, the voltage differential between the copper ground wire and the neutrals should be zero (0)! They are connected together at one point in your main junction box. It's important that they are also connected together in only ONE point for each panel (in case your house is big enough that you might have multiple 220 entry points. But that's very rare.

I have 2 panels but that's only because I have a Generac whole home generator with an automatic transfer switch (so that makes it 3 panels if you count the transfer switch which becomes the MAIN entry point from the meter. So when we rewired, we had to really make sure that the ground was only connected to the Generac transfer switch which takes in the MAIN and isolated at the other two panels.

Notice, I said (WE). No way, as an EE, was I going to allow any installer to mess with my home wiring without me personally assisting and documenting and double/triple checking. And yes, I caught a couple of gawfaws, including the one that the old breaker panel was still being cross grounded, and we had to remove the bolt that connects the ground to the neutral at the old entry box.

If there is any voltage differential between neutral and ground that will cause any GFCI to trip immediately. If it's the same electrician, ask him where he got his license and have him explain the voltage's you see between the two. There should be NONE! If he disagrees, go to the home builder and demand someone else or you will escalate the build to the county inspector!

[mterry63]

Agreed, the voltage differential between the copper ground wire and the neutrals should be zero (0)! They are connected together at one point in your main junction box.

I'm no electrician, but the above statement is a bit of oversimplification without the added statement "when under no load". When a neutral carries current and the ground carries none, the distance and resistance of the conductors comes into play to introduce a measurable voltage between the two. That's one reason why the safety ground conductor is separate, because it should never carry a current under normal circumstances.

Or so I was lead to believe.

[jgreenberg01]

@ drhtmal Here's pics of the wiring.

The switch on the left is a single pole and works fine with a smart switch (the one in my hand and connected with wire nuts came with the ceiling fan).
The switch in the middle is a 3-way and works ok with a GE Jasco or Honeywell smart switch & add-on.
The one on the right is the problem child. Every smart switch using the neutral wire throws the breaker in any wiring combination.

The first post only spoke about when the switches were completely disconnected. With the switches still connected, the breaker on and the 3-ways switched so the light is off - both wires on the right side of the problem child show 120v. The red wire shows 2.5v.

The tape is to let me know which wire was attached to the black screw (common).

Tried to get a pic from above & below to show all connections: