how to wire in GFCI switch/outlet

[lou]

Hi:

I want to put a new GFCI combination switch and outlet into the spot where there was just a light/fan switch before.

The instructions they sent along in the box are for a GFCI dual-outlet unit only, which makes the very good, detailed instructions not so useful.

The GFCI unit is this model:

Everything is labeled quite clearly, on the unit. On the bottom it's got the usual pair of screws for "Line": it tells you to wire the black on one side and white on the other.

On the top of the unit are two other screws for the "Load"; again, one screw for the white wire and one for the hot black.

There are a pair of black wires jutting out of the top of the unit like antenna.

The box I want to install this in (in the bathroom) has the Line cable leading in on the bottom. Then, from the top of the box, a Load cable exits to provide power to the medicine cabinet lights and an overhead exhaust fan. I want the switch to control those lights and the fan.

There is an external ground wire that runs separately from where it's screwed onto the box down into the woodwork where I assume it hooks into the breaker panel or wherever good grounds go to get hooked up.

Nothing is as simple as it seems. I wired the Line wires, white and black, into the bottom screws. Then I screwed the Load wires--those that run to the lights and fan--into the "Load" screws on the top of the unit. Not knowing what the black wires jutting out of the unit were supposed to do, I capped them temporarily. Of course, they probably have something to do with the switch, because now when I restored power from the breaker box, the lights and fan are on all the time and the switch does nothing. Obviously I didn't wire the switch in. At this point I realized I needed to learn more about what I was doing before continuing and so I'm writing here.

How do I wire this up so that the light/fan switch works correctly?

Another question. I was pleased to see that the box was grounded, since this is a somewhat older house. I assume since the box is grounded, I don't have to run a (short) ground wire from the new receptacle/switch to the box? The screws holding the receptacle/switch into the box will provide sufficient contact for ground?

Also, while there is a ground wire running from box to breaker panel, I don't think there is one running from the box to the lights and fan. I probably should install one, right? (As long as I have the walls open and the new drywall not yet installed.) There will be no receptacle on either lights or fan but those should still be grounded, right?

Thanks for any advice.

[Greg]

One of the black wires goes into the load terminal and the other gets wirenutted to the wire going to the fan. They are the leads to the internal switch.

[HaHaHa]

The 2 leads you capped off are the switch leads. Wire one of them to load HOT and the other to the black wire you mistakenly have on LOAD HOT. Leave the white wire you have on the LOAD NEUTRAL where it is.

Those 2 6/32 screws are not considered reliable grounding. You should add a jumper from the GFCI's green screw to the box ground.

Since this room is already gutted, and you said the power feeds up from the bottom, and your cable contains no ground and the home is old - I suggest this:

If at all possible, you should add a 12 awg. 20a circuit homerun to the panel to serve this new bathroom outlet only. Especially if you're in the U.S, as a gutted bathroom constitutes a "substantial renovation" and therefore, if you touch any wiring you must (according to code, but not if you're in Louisiana) bring it "up to code."

You could leave the light(s) and fan on the old circuit and switch, and simply add a separate, brand new box with a regular GFCI duplex receptacle on it's own circuit.

Bathroom lights and fans don't require GFCI protection and in practice, it's not usually done - as it could be more dangerous to sudddenly lose your light while showering at night. [e-mail]