gfciwiring
I have several receptacles with two cables: one has black and white wires, the other – black and red wires. Can I replace these receptacles with GFCIs? If affirmative, how should I interpret the red wire? Thanks!
Followup: The black wires are originally twisted together, and the red and white wires are twisted together, too.
No way from here to know which wire fed the light or fan, but you have a continuous hot feed into the box that fed the receptacle, light and fan. The third wire, maybe it fed the fan or maybe something something else farther down the line, if the latter that needs to be tied in 100 percent to the hot feed. All whites still tied together, blacks to the dimmer from the light and hot. All grounds tied together set with a screw to the metal box. Securing the ground to the box is not needed if the box is plastic.
Before I got too wordy, here is a sketch
Still have to learn to format better
The sketch is a little rough, it should get the idea across I hope
If the previous light was functioning properly and the new light is wired exactly the same and functioning properly, there should be no issues here.
Smells hot could be any number of things or absolutely nothing at all. Usually feels hot is where problems occur (and not feels-hot because of heat generated by the light bulb(s)).
Black/red/white wired in this manner sounds like a multiwire branch circuit in which they have wired your sconce lighting from one of the hot legs (the red). Assuming the proper breaker is being used, this is a completely safe wiring method.
Best Answer
This really isn't that odd and yes you can replace them with GFCI's. It is common with multi-wire branch circuits, or in cases where one outlet is switched and another isn't.
In the case of the black and red wire, one is hot and one is neutral. You can identify which one is hot with a multi-meter or non-contact tester (though NC testers can sometimes be misleading). Do yourself a favor and mark the neutral with white electrical tape wrapped around it once you identify which wire is which.
Don't get too caught up with the wire colours - while you hope people adhere to the standard, there are lots of cases when it's perfectly OK to deviate.