View Full Version : Rewiring bathroom
Jayhawk26
Oct 8, 2015, 12:21 PM
I am trying to wire an existing bathroom light and fan that is on 1 switch to 2 switches. When I took apart the switch, there are 3 black wires, 1 hot, 1 that seems to go to the light AND fan, and 1 that seems to run to the outlet about 2 feet away (the outlet does not work if that wire is not connected to the switch and the switch turned on).
Anyone have an idea how this May be wired and what I would have to do to get the outlet to be on its own and the fan and light to be on their own switches?
donf
Oct 8, 2015, 01:52 PM
Let's try it this way.
Your current installation is one switch that controls the light, fan and receptacle, is that correct and you want an independent switch for the light, fan. The receptacle should be hot all of the time, correct?
We need to be sure that the source of power is the feed to the switch. Also ,the receptacle needs to be a GFCI receptacle and since this is a bathroom, the circuit should be on a 20 amp circuit.
This means that the cable from the circuit breaker to the receptacle must be 12/2 w/g AWG.
The solution is straight forward if the feed to the switch is the hot feed. If the feed to the current setup is a switch loop it is quite a bit more complicated.
If the switch's outlet box contains the black feed to the switch and the white (Neutral) along with the bare ground, this is what you do:
1) The black feed needs to be pigtailed. The source + the feed to the light switch + the feed to the fan and the feed to the receptacle need to be capped together.
The feed to switch one goes to the bottom of switch 1, the feed to switch 2 goes to the bottom of switch 2. The feed to the receptacle goes to the input of the receptacle. The whites (Neutral) for each outlet need to be connected to the feed cable.
Again, you need to be sure that the circuit is a 20 amp circuit and that the receptacle is GFCI protected. Because you are also feeding two switches, the entire circuit cannot be on a GFCI breaker. If it is, then the lights will go out if the receptacle GFCI causes the breaker to trip.
Jayhawk26
Oct 8, 2015, 03:36 PM
When I look in the breaker, it shows it is only 15 amps.
I bought 14/2 wire, so should I return that for 12/2 even though it's only 15 amps? I'm not sure the size of the wire that is already there. I believe I just need the wire to run from either the light or the fan.
I have a switch with 2 rockers on it, so let me see if I have this correct... pigtail the source wire with a small piece to the switch and the black wire going to the outlet.
All of the neutral wires are pigtailed together and not connected to anything, should that be changed?
hkstroud
Oct 9, 2015, 04:26 PM
Describe the wiring in the outlet box.
You said there are 3 wires in the switch box. How are they connected? Are these 3 wires in the same cable?
Missouri Bound
Oct 9, 2015, 10:22 PM
Absolutely not. Unless you are rewiring the circuit from the panel to the bathroom you do not need 12 ga. Wire.
Adding larger wire to an existing circuit is a no-no and could have some ramifications should the next owner ASSUME that the circuit is 20 amp rather than 15.
Zarakali
Oct 10, 2015, 10:20 PM
I agree with you suggest a best way for bathrooms light management Mr. Donf. Thanks for this idea.
donf
Oct 11, 2015, 09:12 AM
Jayhawk,
As Missouri Bound, stated you do not want to mix the gauge of the cables.
Clarification on my answer for you. Current level electrical code requires a 20 amp circuit for a bathroom. One circuit is fine for a single bathroom or you can have one circuit supply the light and fan configuration and a 20 amp circuit supply the receptacle. You can also place another bathroom on the same receptacle circuit.
Why? Because of the higher amperages used by hair dryers or curllers a 15 amp circuit may not be sufficient any longer.
So, there are two methodologies available to you. You can rewire the switches for the light and fan and leave them on the existing 15 amp circuit. Then run a completely new 20 amp circuit (20 amp breaker, 12/2 AWG cable, and install a 20 amp GFCI protected receptacle)
Personally this is the route I would use. That keeps the light and fan on a separate circuit so that if the receptacle trips out, the light is still working in the room.
I's already discussed the rewiring of the bathroom using one 20 amp circuit for the entire room.