I'm back with more "finishing basement" questions.

This weekend, I wired my bathroom. This is 20 amp service with 12 ga wire. For the bath fan/light, the power source came into the switch box (1 box, 2 switches) on a 12/2 wire. From there, power goes up to the light/fan on a 12/3 wire. Red goes to the fan, black goes to the light, white connects to two white wires in the light/fan unit, and ground connects to the green wire in the light/fan.

The light works, the fan does not. My hunch: for the ground wires, I tied the power source ground with the ground that goes to the light, then pig-tailed it and connected it to the ground screw on the LIGHT switch. Assuming everything else is wired correctly (which I haven't checked, but I will tomorrow), would my failure to connect the ground to the FAN switch cause the fan to not work?

2nd question:

All the diagrams in my wiring book say that in the box, I should connect the ground to the box as well as the outlet or switch that's in the box. However, I'm using plastic boxes and there's no place to connect the ground wire. So the book says in that case, ground it to the screw that goes into the outlet box. What a pain. Is this necessary? are there any alternatives?

thanks so much in advance...
trip

tkrussell

The way you described the balc,red,white connections is fine, the fan should work. May be a bad switch, or fan motor, or a loose connection.

Not having the ground connected will not affect the operation of the fan or light. The ground is there in case the hot wire or the fan or light shorts out the the supporting metal frame.

Then the current will be drained off and cause the breaker to trip. The ground is the most important wire in an electrical system, since it is there for safety.

No you do not need to connect to the plastic box, only wirenut all the grounds together with a pigtail to each switch. The alternative to grounding switches is to use a plstic plate and plastic screws, htis will keep all metal away from anyone using the switch.

bbeard33

This may be a dumb question, but did you pigtail the fan switch and the power source together?

I just wired a similar setup and have several pigtails (neutral, power, ground) and it could be missed with that tangle of wires in the box.

triptrop

I did. Turned out the problem was a bad connection in the fan unit. Works great now!

thanks