New Circuit for Bath Heater/Vent, Part III
2007.06.30
Today I continued the work from last weekend on the new bath circuit. I figured I was going to have to wire up the heater/vent unit in the attic. Unfortunately, the wire enters on the far side, back where the roof comes down. I wondered about using a handheld mirror to see what I was doing but… didn’t seem like that would work. I decided I would have to pry the nails out that were holding the unit in place, so I could pull it up and over to a more workable position.
After poking around investigating the possibilities (lying on my stomach on a piece of cardboard across the ceiling joists), it didn’t look like there was any way for me to pull the nails out.
I went back down and took the cover grill off the unit. I then realized I could remove a screw, and pull off a metal cover that enclosed the wiring area. Aha! I can do all the wiring on a stepladder from below. All I need to do in the attic is fish the wire into the unit. Wow, this is the second thing that has ever gone unexpectedly right for me!
While I was up in the attic, I took the time to wrap some foil tape around where the flexible aluminum duct attaches to the little plastic connector flange for the vent exhaust. I then got it in place and used more foil tape to hold that together. Previously it had a bad habit of coming partially detached, defeating the purpose of the duct (and occasionally blowing cellulose insulation down from the attic).
Wiring the heater/vent unit
Back down in the bathroom, I wired up the heater/vent unit. In the unit, the three hot wires were black for the light, blue for the vent fan, and red for the heater. I twisted the black and blue wires together with the incoming black, and the red to red. All the neutrals twisted together, and the green ground connected to the incoming bare ground wire.
It wouldn’t have mattered electrically if I had switched what the incoming black and red wires connected to, but this way is logical if someone else needs to check the wiring later on.
Changing two switches to a switch and outlet
Next I turned my attention to the existing switches next to the door. As I started pulling them out and taking a closer look, I realized that they had not even bothered connecting to the ground terminals on the switches. Granted, the chances of getting electrocuted on a switch or the light on the ceiling are pretty slim, but still.
I disconnected the two switches, figuring out in the process what each of the three sets of wires coming into the box was. I used a couple bits of electrical tape to mark the incoming power, and one for the outgoing light connection. The third wire was now dead, previously going to the vent fan.
I tried to pull that wire out from either the attic or through the box, but couldn’t get it to budge. Must be stapled inside the wall somewhere. Oh well, it doesn’t do any harm to leave it there, just pushed out of the box and back in the wall.
To make sure I had correctly identified the incoming power, I temporarily wired up the receptacle, put the tester in, and went down to turn on the breaker. Yep, that’s it. (Need I mention that I turned the breaker back off before continuing?)
I decided that I really should use a new plastic box, rather than this spray painted metal one. So, another trip to Lowes because of course I didn’t think of this possibility last time I was there…
Electrical 201 continued
This setup, with an always-hot receptacle and a switch for the lights, was not too bad, but again required thinking it through first.
The incoming and outgoing ground wires twist together with two pigtails from the ground terminals of the receptacle and the switch. The incoming and outgoing neutral wires are twisted with one from the receptacle. The incoming hot wire connects with two pigtails from the receptacle and the switch. Then the outgoing hot wire connects to the other terminal on the switch.
I finished the wiring, pushed everything into the box and screwed it all down, with the cover plate. Then I went down and turned on the breaker and came back up.
Um, the light is on when the switch is in the down position. Switch up, light off. Nice. I must have reversed the incoming and outgoing hot terminals. So I turned the breaker off, took the cover plate off, unscrewed the switch, unscrewed the hot wires, reversed them, tightened the terminal screws, screwed the switch back in, put the cover plate back on, went down and turned the breaker back on, and came back up.
No difference. Right. Duh, I guess I put the switch in upside down. So I went back down to turn the breaker off, then back up, took the cover plate off, unscrewed the switch and the receptacle, turned the switch right-side-up (which nearly didn’t happen because of how I’d wired everything together and the tight tolerances), screwed the switch and receptacle back in place, put the coverplate back on, turned the breaker back on… ok, now it’s right. Pbbbt.
The new switch I bought has a little green LED inside that glows when the switch is in the off position. Kinda cool, I thought, and with outlets right next to the switch, I figured it would be good to give you an indication of where the switch is.
The rocker switches came with little stick-on labels, so I put the appropriate ones in place.
Running wire into the panel
Well, with all the wiring done in and around the bathroom, it was time to run wire back to the panel and hook up a new breaker.
The first step was to drill a new hole in the 2x4 on the side of the panel, so I could run the wire through and down. Well, actually the first step was to turn off the main breaker.
Then I fished the wire through some 1/2-inch flexible conduit for the exposed run to the panel, like the electrician had done with the garage line. I used little straps and screws to hold it in place under the other one.
I wove the conduit through a mess of other wires and down through the top of the panel. A special connector screws into the conduit, then fits down in a punched-out hole in the panel, and a nut screws into it from below to hold it in place.
Wiring a new breaker
I stripped off the sheathing back up to the top of the panel, and separated out the hot, neutral, and ground wires.
I basically followed what the electrician had done with all the other circuits. The neutral and ground wires come down, turn, and sit under two available setscrews on the neutral bus. The hot wire comes down, turns, and is screwed into the new breaker. Then the breaker snaps into place.
Now, the moment of truth. I turned the main breaker on, then the new breaker. Then I went upstairs and pushed the switches. Vent/light ok. Heater ok. I rock!
Tune in next week when the house burns down.
Bath Heat, Part II