We have a double switch by our front door that controls the lamp post light and light above the front door. The lower switch began making a humming sound recently so figured it was time to replace it.
Popping it out, I got confused. Not sure how old it is, but as you can see there are two separate enclosures. Red and black are going to the bottom, green connecting the two switches, and then that good old antique wire coming out the top to (I believe) the fixture above the door.
I’m guessing (and will test) that the black is hot, red is neutral for lamp post, and old wire is neutral for overhead fixture. Green is a lazy excuse instead of pigtailing it.
Would that be your assumption?
(obviously I will be testing for actual hot before doing all of this and not going on assumptions before installing ;o)
The other question is that this is on a 20amp circuit. I *think* it’s all lighting. Do I need a 20 amp switch for this? The answers seem to be mixed. In fact, the more recent FHB states that a 15 amp should be fine.
Edited 11/28/2009 10:36 pm ET by darrel
Replies
Hey Darryl,
Those are what're called Despard switches. Still available. Can fit three switches in a single-gang space. The yoke has a spot for a third switch.
The switches are only rated for 10 amps, meaning the switched load has to be less than 10 amps.
You're mostly right about the wiring configuration, except the old wire (rubber/cotton insulation) and the red wire are the switched hots going to the two fixtures. The neutral doesn't pass through the switchbox at all.
One of the conventions in knob-and-tube wiring. Because the hot and the neutral wires are separate (i.e., not in a cable with an outlet jacket), they can take separate paths, and usually do.
I'd go the oldest hardware store you have in your area and ask for Despard switches. Or, with only two switches in the box, you could use a more modern switch that allows two switches to fit in a single-gang box. It's called a "stack switch".
Good luck,
Cliff
Despard switch. I learned something! Thanks. Good info.I can't say I'm that much of a stickler for perfect authenticity so I did just go get a 15amp double-switch from the big box. Given that these were only rated for 10amp, I suppose that's a step up already even though its a 20 amp circuit. ;)