I'm currently wiring up a bank of 5 light switches in one large metal 5 gang box and each switch has a ground terminal. Is it OK by electrical code to just connect the bare ground coming in to the metal box to the box itself and not hook one ground wire to each of the 5 switches? I assume if I do this maybe I should also remove the small insulators at each of the screw terminals?

Thanks,
Royce M

Old switches didn't have grounds; but guess what, this is new work. If you were to obtain an electrical permit, you could ask the inspector/ building inspector... Local codes from city to State vary, so ask the powers that be in charge. They are happy to help! Anyway, if in a metal box, a bonding device like clip or screw to the box will ground the entire box. The metal yoke of the switch will make contact with the box through the screw, but not very well. Why not use a little wire and ground them. I've seen people break off the grounding tabs on switches. Why do you need a ground for a switch? To give a path for stray voltage. Not a bad idea to use a little wire; and ask your building inspector.

If the switches have a green ground screw, yes, connect each to ground, and connect to the metal box.Do not remove the insulators.

This is all per the National Electric Code, which each state follows.

What functional importance do the insulators serve?

The switches do all have a green screw.

Thanks,
Royce M

They only hold the screws onto the device. Removing them have no affect on grounding.

If you do not use grounding screws, the screws that hold the device carry the ground. (if it is a metal box that is grounded (with a ground wire and screw, or clip). Like a lot of 60's bx or conduit that runs to metal boxes, the yolk of the device gets grounded (tho not well) when it is screwed to the box. Not saying this is the way to wire. "Removing them..." can affect grounding.

Quote:

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If you do not use grounding screws, the screws that hold the device carry the ground. (if it is a metal box that is grounded (with a ground wire and screw, or clip). Like a lot of 60's bx or conduit that runs to metal boxes, the yolk of the device gets grounded (tho not well) when it is screwed to the box. Not saying this is the way to wire. "Removing them..." can affect grounding.

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Wow. This is confusing. Even for me.

The little square screw retainers have no effect on grounding/bonding.

Technically, if the box is metal and properly grounded/bonded then no ground wire is required to a switch. Most folks will do it anyway as good practice.
NEC 404.9(B)

Stan, can you review 404.9 (B)?

Section 404.9 (B) Grounding. Snap switches, including dimmer and similar control switches, shall be connected to an equipment grounding conductor

The above statement is clear. And it then it continues on dealing with faceplates,and how the switch can accept a metal faceplate:

and shall provide a means to connect metal faceplates to the equipment grounding conductor, whether or not a metal faceplate is installed. Snap switches shall be considered to be part of an effective ground-fault current path if either of the following conditions is met:

(1) The switch is mounted with metal screws to a metal box or metal cover that is connected to an equipment grounding conductor or to a nonmetallic box with integral means for connecting to an equipment grounding conductor.

(2) An equipment grounding conductor or equipment bonding jumper is connected to an equipment grounding termination of the snap switch.

The last sentence in (B) and then (1) are what I am referring to. This is not just about plates.

This is not true, first see Section 404.9(B) above.

Second, there are two types of switches available, if self grounding, then no equipment ground is needed:

1221-2 > Toggle > AC Switches > Electrical Wiring Devices > Products from Leviton Electrical and Electronic Products

But most residential grade not self grounding and need an equipment ground.

1451-2T > Toggle > AC Switches > Electrical Wiring Devices > Products from Leviton Electrical and Electronic Products

Need to know what type of product you have.

That's not how I read it, nor any inspector I know.

Basically (B) says a switch must be grounded. (B)(1) says if the switch is installed in a metal box with metal screws it s considered effectively grounded.

I purchased the switches from HomeDepot

20 Amp Preferred Toggle Switch - Light Almond-R56-0CSB1-2TS at The Home Depot

They are Leviton 20A switches.

For reference the switch is installed in a metal box with metal screws.

Reading through the thread reminds me the question I had in figuring out why there was available on the shelf a "Perferred" and a "Commercial" light switch. The "Commercial" version being more expensive. In looking at them at the store it wasn't at all obvious but now I see the self grounding description on the HD website. Interesting.

Related my grounding concern, from the discussion I'm understanding that It is OK to leave the grounds off the switches (since they are in a metal box attached with metal screws) but maybe good practice to put the ground on anyway?

Thanks,
Royce M

Good practice? Absolutely... an extra 30 seconds per switch and a piece of scrap ground wire... small price for safety.