Wiring bathroom fan from switch

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  #1  
Old 10-28-13, 10:29 PM
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Wiring bathroom fan from switch

Hi,

my wife and I are new homeowners and I'm starting to get into handyman mode! Please pardon any noob-ish terminology.

We need to replace a bathroom fan in our master bathroom. I removed the old one. There were only two wires (hot and neutral) coming out of a cloth-ish covered conduit. The house was built in 1970 so I think most everything is original. I am thinking of getting a NuTone fan and the instruction manual shows hot, neutral, and ground wires, so it looks like I need to run a ground wire to the fan.

The second bathroom has the fan powered on by the light switch, so I'm guessing it's the same in this one. The master bathroom fan was nonfunctional. In both bathrooms there are dual outlets and a light switch covered by a plate. I opened up the wall plate for the master bath and saw this:

[ATTACH=CONFIG]20118[/ATTACH]

I kind of feel like I should replace the whole thing!

There are two conduits coming into the box. Conduit A has hot, ground, and neutral coming out. Conduit B has hot and neutral.

Hot A goes to the switch connector 1.
Black goes from switch connector 2 to a black splice.
Ground A goes to the outlet.
Neutral A goes to the outlet.

Hot B goes to black splice.
Neutral B goes to the outlet.

Black splice has a wire to outlet.

So ... I think conduit B runs up to the fan?

I'm thinking I just need to buy this:

Cerrowire 25 ft. 14/2 NM-B Wire-147-1402AR at The Home Depot

and then

1. splice the ground wires together and cap them
2. replace the existing hot and neutral from Conduit B going to the outlet/splice with the new wires
3. run the new wires up to the fan, and connect away.

Does this sound correct?
 
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  #2  
Old 10-28-13, 10:59 PM
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Since you have metal conduit you can take the ground directly from the box at the fan end. You should see a small tapped hole (10-32) that you put in a green ground screw available from many home centers or electrical supply houses. The ground from the fan will go to that screw.

If you would like to install a ground wire in that pipe..... go to a home center to the bulk wire rack. Pick up a piece of green, white and black THHN wire. They have the wire on big spools and cut what you need. You would get #14 or #12 THHN depending on what is currently in use. It looks like #14. Use one of the old wires to pull in the new ones.

You wouldn't want to try to pull NM-B thru a pipe... plus it's technically not acceptable by code.
 
  #3  
Old 10-28-13, 11:09 PM
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Not sure why your messing with all those wires and outlets.
Just connect up the black and white wires on the new fan and disregard the ground.
It was common in older houses to not have a ground and unless you want to commit to rewiring the whole house all the way back to the panel just move on.
I would replace the outlets in the bathroom with GFI outlets.
Still would not be grounded but would now not kill you and would meet code.
 
  #4  
Old 10-29-13, 12:47 AM
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If there's no issue with not grounding the fan then it'll make my life a lot easier.

So it seems that it's still acceptable to replace the existing outlet with a GFCI outlet (is that the same as a GFI outlet?) and ground the outlet. The fan wouldn't be grounded but it's still OK?
 
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Old 10-29-13, 07:23 AM
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I would replace the outlets in the bathroom with GFI outlets.
Still would not be grounded but would now not kill you and would meet code.
There is a ground wire at the switch box so the new GFCI receptacle can be properly grounded.

So it seems that it's still acceptable to replace the existing outlet with a GFCI outlet (is that the same as a GFI outlet?) and ground the outlet.
Same thing. GFI means Ground Fault Interrupter and GFCI means Ground Fault Circuit Interrupter.

The fan wouldn't be grounded but it's still OK?
The fan was probably grounded by the conduit.
 
  #6  
Old 10-29-13, 09:05 AM
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I think my noobish-ness is potentially leading people astray. When I say "conduit" I don't mean some metal tube. It's like a metal hose with the inner wires wrapped in cloth. Does that make a difference?
 
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Old 10-29-13, 09:14 AM
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That is a type of flexible conduit. The older steel jacketed cable is called BX or steel armored.... that's what you have. That steel jacket carried the ground.

The newer style of "BX" is MC (metal clad) and has an aluminum armor and a green ground wire.
 
  #8  
Old 10-29-13, 10:46 AM
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Based on your first reply, there's probably a screw hole on the fan to which I would attach the ground wire coming from the fan?

So then it would be:

black wire from conduit to black wire on fan
white wire from conduit to white wire on fan
green wire on fan to green screw on fan

I'll probably replace the outlet with a GFCI outlet as well.

Is it typical in bathrooms to "reverse" the light switch? Meaning, if I turn the switch to "on", the lights in the bathroom come on but the outlets are OFF. When I turn the switch to "off", the lights go out but the outlets are ON. I tested by putting a night light into the outlet. I guess this is specifically for night lights? That seems odd for appliances - in order to use a hair dryer or something you have to turn the lights off? Or am a I really missing something here?
 
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Old 10-29-13, 11:45 AM
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Is it typical in bathrooms to "reverse" the light switch? Meaning, if I turn the switch to "on", the lights in the bathroom come on but the outlets are OFF.
No. The receptacles should be independent of the switch. That is accomplished in one of two ways usually. Power goes to receptacle first then the switch or the power is split one line going to the receptacle and one line going to the switch.
 
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Old 10-29-13, 01:19 PM
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there's probably a screw hole on the fan to which I would attach the ground wire coming from the fan? ... So then it would be: ... green wire on fan to green screw on fan
No. Parts of an electrical system should already be internally bonded to the extent they need to be. The fan needs to be bonded to the low-impedance path to earth. It sounds like that would be the cable jacket. If there is already a mechanical, conductive connection that does that, then nothing more should be needed.

I'll probably replace the outlet with a GFCI outlet as well.
Not all bathroom outlets need GFCI protection, but all receptacles in bathrooms do. You should install a 15A GFCI receptacle here if the protection does not already exist upstream - in the panel or another bathroom, for example.
 
  #11  
Old 10-29-13, 03:05 PM
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I apologize for the ignorance, but am very appreciative of all that's been said.

Regarding the switch, it sounds like I need to wire the outlet first, then run wires to the switch, essentially switching the existing wiring layout I described originally. Is that correct?

For the ground - how would I connect the ground wire from the fan to the cable jacket? Just attach it to the cable jacket and wrap electrical tape around it?

If I wire the outlet and switch as I described above (so that the outlet is always powered and the switch will only trigger the light and fan), but replaced it with a GFCI outlet with load going to the fan I should be OK for both the outlet and the fan?
 
  #12  
Old 10-29-13, 03:11 PM
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Having trouble understanding your initial description but there should be onlyone power in cable. Two pigtails would connect to the black of power in cable. One of those pigtails would got to the line side of the GFCI the other pigtail to the switch. The black from the ceiling would go to the other side of the switch. The neutrals would all be connected to each other and pigtailed to the line side of the GFCI.
 

Last edited by ray2047; 10-29-13 at 04:33 PM.
  #13  
Old 10-29-13, 03:49 PM
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how would I connect the ground wire from the fan to the cable jacket? Just attach it to the cable jacket and wrap electrical tape around it?
If the metal-jacketed is connected to the fan housing with a metal clamp, that should ground the fan. You can ignore the ground wire. It's for use with other types of cables.

If I wire the outlet and switch as I described above (so that the outlet is always powered and the switch will only trigger the light and fan), but replaced it with a GFCI outlet with load going to the fan I should be OK for both the outlet and the fan?
I would NOT power the fan and light from the LOAD terminals on the GFCI receptacle. I would wire everything in the 2-gang box the way Ray described it.
 
  #14  
Old 10-29-13, 09:17 PM
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It doesn't matter what kind of metal clamp? Just needs to be something metal connecting the flexi-conduit to the fan housing?

Finally, nothing goes into the load side of the GFCI? And that should make the outlet "always on" and the light switch on/off toggled?

Thanks in advance, I think I'm ready to get started!
 
  #15  
Old 10-29-13, 10:17 PM
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It doesn't matter what kind of metal clamp? Just needs to be something metal connecting the flexi-conduit to the fan housing?
No. First of all, you aren't working with "flexi-conduit." You're working with metal-jacketed cable, known as MC, AC or BX. That cable needs to be secured to every enclosure it enters. That can be done with a clamp that's built into the enclosure or with one that's field-mounted in a hole made in the enclosure.
 
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