Replacing switches in bath 4-function exhaust/heater/lights unit

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theorbo

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Hello - thanks for checking out my issue. I've reached the limit of my knowledge and am ready to call in an expert but figured I'd see what the experts here would recommend. I'm definitely not an expert but do feel that I have a solid grasp of the caution and care that needs to be taken while doing any electrical work.

I purchased an older 1950s/60s-era home a few years ago and I have wanted to change the switches that control a Nutone 9093WH multi-function bathroom exhaust/heater/light/night-light. My goal is to put the exhaust on a spring-wound mechanical countdown timer and the other three functions on a single-gang 3-function switch.

I cut the power at the circuit breaker and then double-checked that there was no power coming into this switch box. I unwired the existing switches paying attention to how it was wired. Then I wired the new switches in the manner that I thought was appropriate based on the instructions. When I turned-on the breaker the unit made a very loud buzzing sound that I could hear from quite far away at the breaker-box.

At that point I thought that I had not correctly identified the hot line leading from the panel to the box so I unwired everything and then had all the lines nutted-off and I was going to test to see which was hot. So at this point nothing is connected and the wires are all separate with a nut covering the exposed copper. When I flip the circuit breaker something makes that same sound. As best as I can tell there is nothing else on this circuit to make any noise so I am confused as to how something is being energized with all the wires disconnected from the switches.

I'll provide some pics as well as the rough wiring diagram I've drawn showing how the wires were originally when it was functioning, and how I had wired-in the new switches. Any advice is welcome - barring something obvious that I'm missing i will call in a professional to sort it out.

Some links in case it is helpful:

Nutone installation with wiring diagram:
http://www.nutone.com/common/productDigitalAssethandler.ashx?id=5eeb792d-96cb-469e-ab13-ecf32f0c25b3

Timer instructions:
http://www.intermatic.com/~/media/i...on/timers/spring_wound/fd_ff_instructions.pdf

Combination Switch:
Pass & Seymour TradeMaster Decorator Combination Switch, White
TM8111WCC
http://www.legrand.us/passandseymour/light-switches/decorator/tm8111wcc.aspx#.VsD3vfkrK70

http://www.legrand.us/~/media/produ...esources/instruction-sheets/other/340819.ashx


Thanks,
David

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Which of the black wires is carrying the current (line) to the box? I'm pretty sure that wire is supposed to go where B4 is. So B4 can't be a jumper between the two units. I'm also thinking that the timer needs it's own line feed.
 
Ok all wires not connected and capped off and you turn on power and it makes a buzz. The rest of the circuits is not important at this point as nothing is connected. I’m assuming all the white wires are still combined in the back of the box.

Sounds to me like there is something else on the circuit. When you turn the breaker on and hear the buzz it doesn’t trip? When you hear the buzz you shut it off?

Can you tell where the buzz is coming from?
 
Which of the black wires is carrying the current (line) to the box? I'm pretty sure that wire is supposed to go where B4 is. So B4 can't be a jumper between the two units. I'm also thinking that the timer needs it's own line feed.

Thanks - that is a good question and one thing I didn't do prior to disconnecting it all - I'm living and learning. Based on how the box appeared to be a bundle coming into each 2-switch gang (red, black, white) and then there was this extra white & black. I was hoping that this lone black was my line from the panel.
 
Ok all wires not connected and capped off and you turn on power and it makes a buzz. The rest of the circuits is not important at this point as nothing is connected. I’m assuming all the white wires are still combined in the back of the box.

Sounds to me like there is something else on the circuit. When you turn the breaker on and hear the buzz it doesn’t trip? When you hear the buzz you shut it off?

Can you tell where the buzz is coming from?


Yes, all the whites are nutted-together in the back of the box. And yes, your comments are correct. The circuit doesn't trip and I hear the loud buzzing/humming. It sounded like the noise is coming from above me - where the Nutone is located. Is it possible that whoever installed this ran from the house panel to the ceiling/box where the device is located? And then from that to the switch? I can't figure out what else could also be on the circuit.

Thanks for your feedback, bud16415.
 
It was pretty common in the 50/60’s to wire that way. Power can come to the switch first or to the appliance first and then run down to the switch. In those cases you will see a pair of wires coming down to the switch from a ceiling light or fan or such.

What kind of a breaker is the circuit on? Is it a single or double. When you see a cable with the red and black that can be a 220v multi wire branch circuit were they bring 220 up on one cable and then make two 110v circuits.

I still don’t see how the fan could be getting powered up if the switch controlling it is out of the loop.

You have to try and map out what you have going on.
 
Is the old fan still installed?
Have another look at the white wire that dissapears behind the red in the photo showing all the wires.
 
You need to find the schematic for the original fan install. The PN should be on the old unit somewhere. GOOGLE it.

The unit you are presently installing requires Nm-b 2 wire w-GRD. The circuit is wired with 3 wire w/GRD presently (there is also an additional 2 wire which may be a switch loop). Regardless, you need to verify circuit feed. A NEUTRAL must go to the control unit.

2. The switch installs in a double-gang outlet box. When a
thermostat or timer is used, connect at point marked “T”.

R U going to have the timer on both FAN (VENT) circuits or just the FAN?

I don't see (or fail to see in the instructions the wanted AMPERAGE of the supply circuit, whether 15A or 20A (I would think with the heat lamp it would be 20A). Have you checked code to see if the install calls for GFCI protection?
 
Looking at your before sketch it shows power coming in on B3 the jumper bar is intact on the right side of both switches so B4 wire jumpers power to the other switch. B1, B2, R1 and R2 all go up to do the different things. That’s how it was working.

B3 should be your hot wire. I don’t know how the combo switch is set up, but you need to jumper power between the two switches. On the timer side line should be power and load should be what it controls and B3 has to be jumpered to that line.
 
Some of the tabs on the old switches may be cut and there may be 2 circuits involved. Power could be coming in on one or both the three wires.
 
At that point I thought that I had not correctly identified the hot line leading from the panel to the box so I unwired everything and then had all the lines nutted-off and I was going to test to see which was hot. So at this point nothing is connected and the wires are all separate with a nut covering the exposed copper. When I flip the circuit breaker something makes that same sound. As best as I can tell there is nothing else on this circuit to make any noise so I am confused as to how something is being energized with all the wires disconnected from the switches.

Thanks,
David[/QUOTE]

Did you turn the breaker on just the once, or repeated times to insure that, that was the occurrence?

Your planned installation appears correct.
 
Some of the tabs on the old switches may be cut and there may be 2 circuits involved. Power could be coming in on one or both the three wires.

In the one photo you can see the tab on the old double switch is not cut. And there is nothing connected to the vent screw where R1 is on the other side and seeing as how R1 vent worked you have to assume it was connected. No other way it could all work in the first sketch. My guess is B3 is the black wire right in the center of the box.
 
In the one photo you can see the tab on the old double switch is not cut. And there is nothing connected to the vent screw where R1 is on the other side and seeing as how R1 vent worked you have to assume it was connected. No other way it could all work in the first sketch. My guess is B3 is the black wire right in the center of the box.

R2 B3 ???????? if the tab is not cut you don't need two wires
 
R2 B3 ???????? if the tab is not cut you don't need two wires

B3 is the power coming in R2 is power going out thru Heat switch. B3 power goes thru jumper bar to B4 B2 is power out to night light thru switch jumper wire takes power to second switch and with jumper bar intact it powers light and vent B1 goes to light thru switch and R1 goes to vent thru other switch.
 
In the one photo you can see the tab on the old double switch is not cut. And there is nothing connected to the vent screw where R1 is on the other side and seeing as how R1 vent worked you have to assume it was connected. No other way it could all work in the first sketch.

My guess is B3 is the black wire right in the center of the box.

It appears that the hot pair are entering the right hand center and are labeled as B4.

It also appears that the switch legs are in two 12/3's, one entering the lower right hand corner of the right box and the entering the center of the left hand box.
 
B3 is the power coming in R2 is power going out thru Heat switch. B3 power goes thru jumper bar to B4 B2 is power out to night light thru switch jumper wire takes power to second switch and with jumper bar intact it powers light and vent B1 goes to light thru switch and R1 goes to vent thru other switch.

I will buy that but I still want to know what the noise is?
 
Could be something just happened to come on at the same second and has nothing to do with anything. I had a lightbulb burn out one time just as I flipped a breaker and it drove me nuts trying to tie the two things together.
 
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