Ungrounded dimmer

[NeilG]

I want to install a dimmer on a new LED light fixture. The dimmer has a ground wire, and this circuit is not grounded. Can/should I still use the dimmer and put a wire nut on the ground wire? I can install a GFCI on this circuit if that would help. Thanks,

Neil

 

[NeilG]

I found the answer in the NEC, 404.9(B), exception 1. It's okay if it's a replacement switch.

 

[Jeff Handy]

Make sure the dimmer is compatible with LED lights.
It will say on the package, and/or on the wiring instructions in the package.
And some LED dimmers need a neutral wire, I believe.

 

[NeilG]

Yes, this dimmer is compatible with LED and needs no neutral. Thanks.

Neil

 

[afjes_2016]

NeilG - how do you know this circuit is not grounded? Sorry, I don't know your skill level and reason for asking.

Did you test to see if this circuit is grounded? If so how? If there is a metal box and you don't see a ground wire the box can still be grounded maybe.

Anyway, whether the circuit is grounded or not the switch should still function correctly.

Installing a GFCI upstream of this switch or light fixture box (where ever the power is coming from) won't hurt it and will provide added personal safety especially if the circuit is in fact not grounded. The gfci should not affect the functionality of the switch.

 

[NeilG]

NeilG - how do you know this circuit is not grounded? Sorry, I don't know your skill level and reason for asking.

Did you test to see if this circuit is grounded? If so how? If there is a metal box and you don't see a ground wire the box can still be grounded maybe.

Anyway, whether the circuit is grounded or not the switch should still function correctly.

Installing a GFCI upstream of this switch or light fixture box (where ever the power is coming from) won't hurt it and will provide added personal safety especially if the circuit is in fact not grounded. The gfci should not affect the functionality of the switch.

There's no ground wire in the box. It is (was, I had to break it out and intall a box big enough for the dimmer) an old Bakelite box. One NMC coming in had a white and black, the other a black, a white and a red. The whites were connected, the blacks connected with a pigtail that went to the switch, and the red went to the switch. I probably should have tested to see if those white wires were actually neutral wires, but there's definitely no ground.

The reason I asked was that the dimmer comes with a ground wire and I needed to know if it was necessary for it to function correctly and be safe.