3 gang box, wiring problem

[foghat]

Hi all,

I have a 3 gang box with only one hot wire coming into it. Currently has a bathroom fan and 2 lights. I replaced the 2 lights with 2 ge dimmers.

Right now i have blacks from all 3 switch's connected to the one hot. the difference between this and how the original switches were wired is one switch was connected directly to the hot. And then there was a wire coming from the hot with a section striped - this striped section looped around the bolt on the second light and then the wire continued on to the fan.

Problems is when the lights and fan are on and then I turn the fan off, the lights go off too. Sometimes one goes off, sometimes the other. And does not happen every time I switch the fan off. But if I turn the fan on and off, eventually I can make the lights go off.

Any thoughts? everything seems to be grounded fine.

[foghat]

okay. it seems totally random. sometimes i have to turn the fan off multiple times before the lights will turn off. sometimes one light turns off, sometimes both.

Wondering if a bad dimmer could cause this?

[foghat]

Okay, I have ruled out a bad switch and bad wiring (on my part). I removed a dimmer, put one regular switch in - problem still occurred with 2nd dimmer. removed 2nd dimmer and replaced with brand new one. Problem still occurs with new dimmer. Put in 2nd old switch (same wiring) and lights always work as expected.

A month or so back I had put a ge dimmer in another bathroom (2 gang box). Light and fan. I just tried turning out the light with the fan in this bathroom. I was able to do it, but much more infrequently - I hadn't even noticed this before.

So I guess there is an issue with these switches sharing a hot wire with a fan?

[pbibm]

hey darren

One thing to know is that the total load for these switches drops when you gang them together in a box right next to each other. Check the docs for the switch

How hot to the switches get if they're just sitting there with no load (nothing on). How hot with everything on? I read once that some ge switches have heat sinks on them and there's something to be done with that when ganging mutliples

Paul

[foghat]

hey darren

One thing to know is that the total load for these switches drops when you gang them together in a box right next to each other. Check the docs for the switch

How hot to the switches get if they're just sitting there with no load (nothing on). How hot with everything on? I read once that some ge switches have heat sinks on them and there's something to be done with that when ganging mutliples

Paul

Hi,

Yes the total load drops due to having having to break off some/all ofthe heatsink tabs when ganged together. Even with the the tabs removed I am still well under the reduced load on both the switches. Plus when I replaced with a new switch, I didn't remove any tabs.

I also have another 3 gang box in the house with 2 ge switches (with a higher load) and a regular light switch (no fan) and they work fine. It must have something to do with the fan somehow?

[pbibm]

From what I've read it sounds like you've eliminated the other variables. Fans can introduce powerline noise, but that should not be a problem for zwave which is 100% rf.

Can you get to the electrics of the fan easily and temporarily wire in a light or some other load to prove your point? I know bathroom fan wiring can be hard to get to (especially this time of year in a cold attic)

Paul

[foghat]

The switches may be RF, but 100%? They are still connected to the same power line and can be manually operated which does not require RF at all.

I may be able to replace fan with a light, will have to take a look. If I confirm the fan is the issue, is there even anything that can be done - assuming it is power line noise?

[Pete]

Check out your fan/light combo. I replaced one in one bathroom and rewired it. They are very modular. The old ones had a plug from the fan into a small outlet in the case of the fan. If you disassemble the fan you will see an electrical box with separate wires for both the lighting and the fan. If you have conduit running from the fan box check the number of wires you have in the conduit and add one more. All the new bathroom fans are set up the same these days with separate wiring for the fan and the light.

[pbibm]

The switches may be RF, but 100%?

From a signaling perspective, yes. The circuitry between the what detects the signal and what operates the load should be discrete.

If noise on the line can affect the switch operation, that's a design flaw

Paul

[foghat]

Check out your fan/light combo. I replaced one in one bathroom and rewired it. They are very modular. The old ones had a plug from the fan into a small outlet in the case of the fan. If you disassemble the fan you will see an electrical box with separate wires for both the lighting and the fan. If you have conduit running from the fan box check the number of wires you have in the conduit and add one more. All the new bathroom fans are set up the same these days with separate wiring for the fan and the light.

Yes, my fan plugs into the fan housing. I am able to get the fan out of the fan housing and can see a black and white sitting there wire nutted.

Though I cannot tell how to get the housing out. Seems like this would be more work than it is worth at this point. I may try a different zwave dimmer.

[foghat]

From a signaling perspective, yes. The circuitry between the what detects the signal and what operates the load should be discrete.

If noise on the line can affect the switch operation, that's a design flaw

Paul

Could be. Assuming noise is the issue. I may try a different brand switch.

[pbibm]

Though I cannot tell how to get the housing out. Seems like this would be more work than it is worth at this point. I may try a different zwave dimmer.

A majority of those install from the top but it was worth a look. If you can get to the wirenut to the fan, it would be a quick test.

Also, I missed dimmer when I read before. Dimmers should not be used on a motor load like a fan, which are typically inductive loads. A relay version of the switch is required. This potentially explains the load itself causing odd behavior on the switch portion

Paul

[foghat]

I'm not using a dimmer on the fan itself. The fan has a regular on/off (non-zwave) switch. But all three switches share the hot.

[pbibm]

hmmm. re-reading. Does this look like what you did?:


Hot---------------GE 1------------Light one----Neutral
^-----------------GE 1------------Light two----Neutral
^-----------------Switch----------Fan---------Neutral

[foghat]

hmmm. re-reading. Does this look like what you did?:


Hot---------------GE 1------------Light one----Neutral
^-----------------GE 1------------Light two----Neutral
^-----------------Switch----------Fan---------Neutral

More like this (which may be what yours says as well):

 
              GE 1---------------Light 1
               |
Hot --------------GE 2--------------Light 2
               |
               Switch -----------Fan

Not sure how the neutrals tie in. There is a bunch of them wire nutted together in the box.

The 3 switches are wire nutted to the same hot

This is not so much what I did, but the electrician. Except, as I said earlier, originally there was one wire coming from the hot that connected the light 2 switch inline and then terminated at the fan switch.

So:

              Switch---------------Light 1
               |
Hot --------------Switch--------------Light 2
                    |
                 Switch -----------Fan