# Plastic "Old Work" wall box - Grounding Screws?



## Speedy Petey (Feb 1, 2004)

strohs19 said:


> .........so I can ground the wires per the manufacturer's instructions?


You are not grounding the wires. The wires are the ground. If the box is metal it must be grounded.
You need to twist all the grounds together and leave a tail to ground the devices.


----------



## strohs19 (Jan 14, 2006)

So if I understand correctly...inside the blue plastic wall box I have...I will have the bare ground wire from the power feed, the bare ground wire going to the recessed lights, and the bare ground wire going to the ceiling fan all connected together. The ground wires from the fan switch and the dimmer switch will then both be pigtailed to the other 3 ground wires.

This configuration is what I thought was correct, but the manufacturer's instructions had me confused when they stated the following: "When no ground means exist in the wallbox, then NEC 380-9 exception to (b) allows a control without a ground conection, to be installed as a replacement. For this type of installation, cap or remove the green control ground wire. A control installed under this exception must be provided with a plastic, non-combustible, UL listed wallplate."

I am new to this since this is my first house, so any help is appreciated. I thought this would be a simple project but the manufacturer's instructions had me a bit confused whether I was doing this properly.


----------



## MinConst (Nov 23, 2004)

You only ground to a metal box because the box itself is metal and become live if a short happens. With plastic boxes there is no need to ground the box it is not conductive. As Speedy said just twist the grounds together in the box and wire nut them. From what you asked this is set of switches so a tail is not needed. Both switches need to be connected to the grounds via the green screw. So twist the grounds and two tails together and attach the tails to the switches ground screws.


----------



## Speedy Petey (Feb 1, 2004)

Correct.

strohs19, the instructions you cited do not apply. Those instructions state: _"When no ground means exist in the wallbox..."_
You DO have a ground in the box, the bare wires.


----------

