I am trying to change a regular light switch (2 wires red and black) with a dimmer switch with 3 wires ( 2 black and a green) where do you connect these 3 wires? THX.

I am trying to change a regular light switch (2 wires red and black) with a dimmer switch with 3 wires ( 2 black and a green) where do you connect these 3 wires? THX.
The green wire connects to the either the bare wires or the metal box. If box is plastic then the green can be capped and stowed. Polarity is not an issue unless a white wire is in the box. If not, then this switch leg is a series connection and will not affect the circuit.

Just to clarify something, if the box is plastic, there most likely is a bare wire inside the box, since Romex is used with plastic boxes, and the green wire must connect to the bare. I know this is what Nmwirez meant, but worded it in such a way to imply that if there is a plastic box to always cap the green, which should not be done.

Most dimmers made today are solid state and required an equipment ground.

Just to clarify something, if the box is plastic, there most likely is a bare wire inside the box, since Romex is used with plastic boxes, and the green wire must connect to the bare. I know this is what Nmwirez meant, but worded it in such a way to imply that if there is a plastic box to always cap the green, which should not be done.

Most dimmers made today are solid state and required an equipment ground.


Tx tk, I lost the first reply and shortened up the second one. I agree.