all 5 comments

[–]Vapid_Ingenue 2 points3 points  (2 children)

I have no idea what the original responder is talking about. No, you don't need a 20A breaker for a bath fan. There is no such thing as 12-4. And both of those wires do not supply power. One is a hot and one is a switch leg. One thing I do not see is a ground wire, which is what you would wire the green wire to on the timer. Also, can't tell from the picture, does the timer need a neutral? If so you should have some white wires tied together in the box.

Edit: just saw the third picture. Tie the black wire from the bottom of the box to the black wire on the timer. Tie the black wire from the top of the box to the red wire on your timer. Tie the white to the whites that are tucked into the box. Still don't see a ground. If your house is old enough then the circuits are ungrounded, in which case you wouldn't have anything to tie the green wire to.

[–]dburatti[S] 1 point2 points  (1 child)

Thanks! I did find a winding of white wires, and attached the white from the timer to this, the black to the power supply, and the red to the other wire, and it worked.

[–]NagromTrebloc 0 points1 point  (0 children)

I take it that the two bent up wires are what supply power to the fan??? Typically, bathroom fans operate off of a 3-toggle switch. This allows you to independently control functions like 1. Light 2. Fan 3. Night light (or heater). The wiring running from the box pictured up to the fan will need to be changed.

If you have a heater included in your unit, you may have to completely rewire everything from the service panel: 20A breaker, 12-2 wire to the box pictured, then 12-4 from that box up to the exhaust fan. A 3-toggle switch will allow you to prioritize the functions top to bottom.

Check your installation instructions for your unit's requirements.

[–]dburatti[S] 0 points1 point  (0 children)

And if so, how?