Adding exhaust fan to bathroom - wiring help needed


  #1  
Old 01-23-17, 03:54 PM
P
Member
Thread Starter
Join Date: Jan 2017
Location: USA
Posts: 8
Upvotes: 0
Received 0 Upvotes on 0 Posts
Adding exhaust fan to bathroom - wiring help needed

My bathroom has a single light fixture over the sink that is controlled by a wall switch. All wiring and junction boxes are accessible from the attic.

The wall switch is fed by two 2-wire cables. Each cable has a white, black, and bare wire. The 2 neutral (white) wires are connected by a wire nut, the 2 bare ground wires are connected by a ground nut to a jumper going to the switch, and the 2 black wires are connected to the screw terminals on the switch, one at the top and one at the bottom of the switch.

I plan to install a new duplex box and fish a new 12-2 (w/ ground) cable to the existing switch location. What is the best way to get power to the new fan? Can I use a jumper from the existing black wire to the new switch, and connect the neutral to the existing neutrals?

Thank you!
 
  #2  
Old 01-23-17, 05:47 PM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 29,711
Upvotes: 0
Received 15 Upvotes on 13 Posts
Can I use a jumper from the existing black wire to the new switch, and connect the neutral to the existing neutrals?
Yes. Pigtail the black hot to each switch. Do not put two wires under one screw.
 
  #3  
Old 01-23-17, 07:14 PM
P
Member
Thread Starter
Join Date: Jan 2017
Location: USA
Posts: 8
Upvotes: 0
Received 0 Upvotes on 0 Posts
Thank you! Pigtail - that's the term I was trying to remember.
 
  #4  
Old 02-04-17, 02:54 PM
P
Member
Thread Starter
Join Date: Jan 2017
Location: USA
Posts: 8
Upvotes: 0
Received 0 Upvotes on 0 Posts
I'm back for more help. I have two problems, one is that the timer I purchased has a red wire that is supposed to be wired to the load per the instructions. The other problem is that after wiring the switch as above (neutral to neutral, ground to ground, and pigtail black to the incoming hot line in the box) I'm getting a constant 120 VAC between the neutral and hot wiring for the new fan. In other words, the black coming out of the timer is always hot - the switched output is the red wire.

What is the safest way to wire this? I ran 12/3 for the new fan/switch, so fortunately I have an extra conductor (red color) if I need to wire it to the red from the switch. But if I do that, what do I do with the black coming from the new switch - can I connect the red to the black on the fan and leave the black from the switch box disconnected? Thank you in advance. I thought I could make this work easily.
 
  #5  
Old 02-04-17, 04:53 PM
P
Member
Thread Starter
Join Date: Jan 2017
Location: USA
Posts: 8
Upvotes: 0
Received 0 Upvotes on 0 Posts
Update: It's working, but I'd feel better with a professional opinion. When I wired it the first time I connected the black from the new cable and the black from the new switch to the pigtail going to the existing hot. I disconnected the black from the new cable and connected it to the red wire on the switch - success! So my wiring is as follows:

4 neutrals connected together: one from each of the two existing cables, plus the new switch and the new cable

3 hots connected together: one from each of the existing cables and one from the new switch (I pigtailed the hot from the switch to the two other hots)

1 black, 1 red connected together: red from the new switch, black from the new cable

5 grounds connected together: one from each of the existing cables in the box, one from the existing light switch, one from the new switch, and one from the new cable
 
  #6  
Old 02-04-17, 06:51 PM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 29,711
Upvotes: 0
Received 15 Upvotes on 13 Posts
Usually if a switch has a black and red wire. Power in (hot) goes to switch black and switch red goes to the black to the power out cable if it is only two conductor.
 
  #7  
Old 02-09-17, 10:37 AM
P
Member
Thread Starter
Join Date: Jan 2017
Location: USA
Posts: 8
Upvotes: 0
Received 0 Upvotes on 0 Posts
Thank you!

I appreciate the help and assistance finishing the wiring.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: