Bathroom exhaust/light combo install


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Old 03-10-18, 07:01 PM
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Bathroom exhaust/light combo install

hi. We have an ceiling exhaust fan in our kids bathroom. In our master bath we have an exhaust/light combo that is controlled by two different wall switches.

We only have a single switch in the boys room controlling the fan. What are our options for installing a combo unit here in the boys room? Ty
 
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Old 03-10-18, 07:52 PM
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You will need 3-conductor cable (+gnd.) between the fan/light and the switch. You probably currently have 2-conductor cable.
 
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Old 03-11-18, 10:17 AM
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Why do some cables have a ground and some not? I do have easy access to the attic but there is a crap ton of blown in insulation. If I can find out where the cable for the light switch is running I should be able to install another right?

I initially wanted to add a light over the bathtub because its like a cave in there, and then I saw they have LED exhaust fan/light combos and thought that may be an easier solution
 
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Old 03-11-18, 10:50 AM
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In the early 50's or so.... the first NM (non metallic) cables did not have a ground. The ground is now required in all NM type cables.

You may be able to see the wire running from the light fixture box down to the switch. Depending on how many wires come into the top of the switch box.... it may be easier to abandon the old two wire cable and replace it with a three wire cable. You need to know where the circuit gets its power.... at the light or at the switch.
 
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Old 03-11-18, 04:29 PM
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Under latest code if power comes in at the fan you may need 4-conductor cable because the switch box needs a neutral even if not used. You need to check with your local inspector they may still allow 3-conductor cable.

If power comes in at the switch than 3-conductor cable is okay.
 
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Old 03-13-18, 11:39 AM
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Sorry for the dumb questions.

1) What exactly is a 4-conductor cable? I can't find anything explaining it online. Is a 3-conductor white, neutral, and ground?

2) Also, how do I determine if power comes in at the light or switch?

Thank you
 
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Old 03-13-18, 12:01 PM
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Four wire cable is black, red, blue and white. It's used for multiple switches in one cable.

Turn the power off to that circuit. Pull the switch out of the box without un-wiring it.
What do you see ?
 
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Old 03-14-18, 09:21 PM
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Thanks. We are getting our new exhaust fan/light next week. After I take a look at the wiring for that and see what is going on in our walls I will follow up.
 
 

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