Branch circuit is simply a circuit from your panel to whatever it serves. You will hook your 12/2 to a 20 amp breaker and you will have a 20 amp branch circuit.
Typically, I use four switches on these units.
Fan, light, heater, night light.
You don't want the night light on 24/7
You can run your new circuit in with the existing light circuit but it would be more difficult for you and you would now have five switches. My limit is four because the materials are easier to find.
Typically I would run the new 12/2 down the wall, into a 4 gang plastic junction/switch box.
I would run two 12/3's from the switch box to the fan/light/heat/nl junction box. This in itself can be quite a challange because the JB's are often very small.
The wiring in the switch box is pretty simple. Bare grounds all together leaving pigtails for each of your switches.
Switch box:
White wire (neutral) from your incoming 12/2 ties to the white wires in the 12/3's going to the fan/light.
Black wire from your incoming 12/2 is your 120v power. Install 4 pigtails on it, one to power each switch.
The remaining wires(red/black, black/red)are your switch legs. They will carry current to the fan,light heater and night light. Hook these to the corrosponding wires in the fan/light JB. Mark them to keep them straight.
example.
Black/red #1 = light/night light
Black/red # 2 = heater/fan
EDIT:
I didn't really understand the type of switch you are using but the wiring will be the same as if there were 4 individual switches. Maybe you have one, two gang switch that does all functions?. If so, change the existing lihjt sw box to whatever size you need and keep the existing light switch wiring completely separate, just how it is.
Typically, I use four switches on these units.
Fan, light, heater, night light.
You don't want the night light on 24/7
You can run your new circuit in with the existing light circuit but it would be more difficult for you and you would now have five switches. My limit is four because the materials are easier to find.
Typically I would run the new 12/2 down the wall, into a 4 gang plastic junction/switch box.
I would run two 12/3's from the switch box to the fan/light/heat/nl junction box. This in itself can be quite a challange because the JB's are often very small.
The wiring in the switch box is pretty simple. Bare grounds all together leaving pigtails for each of your switches.
Switch box:
White wire (neutral) from your incoming 12/2 ties to the white wires in the 12/3's going to the fan/light.
Black wire from your incoming 12/2 is your 120v power. Install 4 pigtails on it, one to power each switch.
The remaining wires(red/black, black/red)are your switch legs. They will carry current to the fan,light heater and night light. Hook these to the corrosponding wires in the fan/light JB. Mark them to keep them straight.
example.
Black/red #1 = light/night light
Black/red # 2 = heater/fan
EDIT:
I didn't really understand the type of switch you are using but the wiring will be the same as if there were 4 individual switches. Maybe you have one, two gang switch that does all functions?. If so, change the existing lihjt sw box to whatever size you need and keep the existing light switch wiring completely separate, just how it is.
