does a switch in an old work box require a ground?

jheavner

I replaced a light on a pull chain with a wall switch. The light had 14/2 romex going into it and I made the mistake of assuming the ground was actually grounded and used all three wires to wire the switch. It turns out the romex is spliced into some old two-wire in a junction I've yet to find but other outlets on the circuit are definitively two-wire. Is it ok if I just have hot and neutral in a plastic old work box for a light switch?

Stubbie

If your looking for the code compliant answer, you would not be able to do this type installation. Reason is you 'added' the switch you did not replace a non-grounding type switch that was existing. If the NEC allowed extension and additions for devices from branch circuits that don't have the equipment grounding wire this would defeat the safety improvements they have mandated to get away from 2 wire type installations. There are situations where you can do... what you did.. for receptacles.. but that's a different story entirely.

Now if you elect to keep this arrangement of yours I would make sure that I never use a metal cover plate and if possible put the light on gfci protection. This will give you some added safety towards electrocution in case of a ground fault.

jheavner

I was expecting that answer. Is there any code compliant way to wire a two-wire light to an external switch when the circuit has been wired with romex?

Is it a code violation to bring two-wire into a junction and bring romex out of that junction?

What about my attic fan? I don't know when it was installed but it comes out of the same junction box as the light and is on ungrounded romex.

InPhase277

Like Stubbie said, it isn't exactly code compliant, but in the practical world, it isn't the end of all life as we know it. We ground things that have exposed non-current carrying metal. What you don't want to do is actually connect the ground conductor to either end, because if there is a fault at one end or the other, then the ground would allow the voltage to leave the area and be available at the other end. And there are plastic plate screws available.

I would say that ideally you'd change the wiring in the circuit to grounded wiring. Barring that, it would be nice to have the circuit GFCI protected. And foregoing that, you could eliminate any exposed metal, such as the plate screws.

jheavner

Ugh, if I'd have known it wasn't grounded I could have easily put a GFCI in front of it but I covered the wall with paneling and that's going to increase the fun factor. I could put it in the attic but that would be a PITA to go up there and reset it if it trips. Thanks guys, I'll put a plastic face plate and screws on it for the time being and figure out what I'm going to do.

InPhase277

You could also put a GFCI breaker in the panel and protect the whole circuit.

jheavner

You'll have to forgive me, I've never heard of a GFCI breaker. That's intriguing, I'm going to have to learn more about that.

nap

all GFCI protection used be be only with a GFCI breaker. The combination devices (recep w/ GFCI protection) came later.