I am wiring a brand new switch box with 3-gang electrical box
Which has 6 wires going into it.

What is the best method for connecting the 6 ground wires together
Then connect ground wire from these 6 wires to 3 switch's ground
Screw.

I have seen a few techniques, but they all seem to have
Some sort of draw backs. For example, the electrician that wired
Our house 20 years ago, connected all the 6 grounds with a copper
Ring, then cut off 3 of the 6 ground wires down to the copper ring,
And had the other 3 go to the switches. This made three wires
With very short ground wires. Although this method seems
To be fine with the code, I like to find a way to improve my
Technique for the new switches I am wiring. One method that
I've tried with 2 gang switch boxes with 4 wires going in,
Was to twist the 4 grounds with another 2 ground pigtail with
A wire nut, then use the pigtail to go to the switches, which kept all the
Ground wires long. I always use the highest cubic inch capacity so
That there would be plenty of room.

Metal box?

See: IDEAL INDUSTRIES, INC. - Grounding (http://www.idealindustries.com/products/wire_termination/grounding/)

Use a 3 wire combo tail for the switches screwed into the metal box orr three separate stranded grounding screw to fork terminal grounding pigtails.

And a green term-a nut to fork terminal to terminate the 6 grounds to the box itself.

Plastic box

Three stranded wire to fork terminals to wires to the 6 ground wires with a wirenut.

Thanks for the reply.

I looked at the link and I understood the method you are describing for the metal box. I am using the plastic box. Did I understand you correctly that, you are suggesting to use 3 stranded wires, one for each switch, and then connect the 3 strand and 6 solid copper wires (9 total) to a wirenut? That would require a big wire nut (I have them) which may be hard to fit in the plastic box. The regular size wirenut can only have up to (5) #12 solid wires. I am using #12 solid wires.

Romex?

Anyway, there isn't fundamental reason why all of the grounds have to be connected together in the plastic box.

Just take the related grounds to the switch and use the term-a-nut method (3) and connect to each switch with the fork terminal.

All equipment grounding conductors need to be connected together, and one can be left longer, or use a pigtail, to connect to the green grounding screws on each switch.

This is required to insure continuous connection of equipment grounding to each cable.

Thanks tkrussell,
I'll connect all the grounds together either with a pigtail, or a copper ring.

TK brings up a valid point which I saitisfy. Whether the inspector considers it OK is another matter.

The Romex is protected because the grounds would make it to the electrical box at one point. The switch is protected because it get's the ground screw. The box is double insulated, so it's protected.

If a metal plate is used, then it bridges all of the grounds, and the plate gets grounded. Loops in grounds are best to be avoided and independent grounds to the panel with an isolated plate is the best way to accomplish this.

The independent signal and protective grounds is routinely used in hospitals (orange outlets). In fact, there may actually be two independent busses in the panel.

Will it get flagged. Don't know.

If a metal plate is used, then it bridges all of the grounds, and the plate gets grounded. Loops in grounds are best to be avoided and independent grounds to the panel with an isolated plate is the best way to accomplish this.

The independent signal and protective grounds is routinely used in hospitals (orange outlets). In fact, there may actually be two independent busses in the panel.

Will it get flagged. Don't know.


What metal plate are you referring to?

Why even mention Isolated Grounding? It is irevelvant in home, and most of commercial and industrial wiring, hardly used even in datacenters.

NCR still requires IG for their equipment, only issue is they don't realize what is needed to be done for a true IG.

The eustecheon plate (cover plate) can be metal, plastic or wood. It's typically plastic these days.

Oh I see what you mean by "If a metal plate is used, then it bridges all of the grounds, and the plate gets grounded.".

Sorry, that is not allowed, each device needs a ground wire.

Plates are often painted, get loose, and are not UL Listed to be used as a grounding or bonding jumper.

Yep, each device needs a ground wire. I don't disagree.

Each device in the plastic box get's it's own ground and it's BEST to keep the related grounds the same. Ground to switch #1 goes to poles of switch #1.

Grounds of switch #2 goes to poles of switch #2. etc.

Plastic box: No grounds required to the box.

Nice and neat, just connect the Romex ground to the related switch ground terminals. There is no need to connect all of the Romex grounds in the box to themselves. Each switch is grounded.

Maybe useless info, but you can have 2 groups of grounds connected by a ground jumper to fit in two wirenuts.

You would be the first to consider this:


it's BEST to keep the related grounds the same. Ground to switch #1 goes to poles of switch #1.

The first thing done to splice a switch box, or any box for that matter, is all equipment grounds are gathered, formed, and twisted to fit in the back of a box. A mechanical connector is applied, and often, if a barrel crimp or a Greenie wire nut is used, one wire is left long enough to connect to each ground screw on each device.

Equipment grounds are all common, and I have not met an electrician yet that will worry which EGC from which cable must connect to it's respective device.

An experienced electrician that has learned the hand motions and technique of splicing can do a box is a few minutes. There is no reason at all to do do as you suggested.

tkrussell, a question about the attached picture: Picture shows one long ground wire in the front laying down on the bottom side of the plastic switch box. This box looks like was for three switches. Can you discuss how this one long wire gets attached to three switches. I can fill in the blanks, but I rather let the pro explain it.
My goal is for the neatest solution (and avoiding putting 6-9 wires in a wirenut) I can find that would be NEC and local codes compliant.
Thanks

Abc, If I was to guess, I would think he is going to use that 1 wire to connect to the switches, in series. This would count as 1 wire, not 3.
You can still use 2 groups of grounds and have a jumper between both wirenuts.

Wiring the grounds of each switchloop romex to the individual switches does not seem to violate article 250.148

Particularly


(250.148d) Nonmetalic boxes: One or more equipment grounding conductors brought into a a nonmetalic box shall be arranged such that a connection CAN be made to any fitting or device in the box requiring grounding.

It does NOT say that all of the grounds must be connected together.

EDIT:
Ground integrity is maintained and each device in the box is grounded per NEC using the one cable per switch method where the ground and the swich loop is connected to each switch respectively without a cross ground connection to any other switch.

It does not seem to violate the NEC 2008.

People are just applying the metal box technology to plastic boxes without re-education.

Furthermore, the combining of grounds creates ground loops. From an engineering point of view, not combining makes sense. I believe the NEC agrees, and the OP should site 240.148d as to why it was done that way if questioned.

Kiss, please read the beginning of Section 250.148:

Continuity and Attachment of Equipment Grounding Conductors to Boxes.

Where circuit conductors are spliced within a box, or terminated on equipment within or supported by a box, any equipment grounding conductors(s) associated with those circuit conductors shall be connected within the box or to the box with devices suitable for the use in accordance with 250.148(A) through (E).

That is Code-ese for all bare wires get connected together in a box.

The line item (D) you highlighted states that each switch must have a separate connection to those grounding conductors, satisfied by the long wire ready to be connected to the green screw on each switch.

Without cutting, a loop is made in the wire and hooked onto the green screw, with just the right amount of jumper wire between each connection, and the end scrap is cut off.

This is one technique I mentioned that is learned during on the job training.

If you have 6 cables coming into a box, all 6 must be spliced, and one connection shall be arranged for each switch, and it said "one or more".

Sure you can have 9 wires and a huge wirenut, but my method is what makes the Greenies wirenut, with one hole at the top of the wirenut, for one wire to be long enough to loop from device to device, so popular.

I asked the question in Mike Holt's forum: 3 gang plastic box ground clarification - Mike Holt's Forum (http://forums.mikeholt.com/showthread.php?t=123420)

It's getting interesting.

Sure you can have 9 wires and a huge wirenut, but my method is what makes the Greenies wirenut, with one hole at the top of the wirenut, for one wire to be long enough to loop from device to device, so popular.

tkrussell, I created a drawing from what you've explained, above.
Does my drawing reflects what you are trying to tell us?

Thanks
Abc

abc, If I was to guess, I would think he is going to use that 1 wire to connect to the switches, in series. This would count as 1 wire, not 3.
You can still use 2 groups of grounds and have a jumper between both wirenuts.

Stratmando, Does the drawing I made looks like what you are suggesting?

I leave it up to the pros to decide. Which drawing, on page 2 or page 3, should I go by when I am wiring my 3 switches with the 6 romex wires going into the plastic switch box? Which one pros would prefer, which one is neatest? And of course, both drawings are NEC code compliant, correct?

Yes, could even just use just 2 red wire nuts, an have 6 wires in 1 and 5 wires in the other, with 3 of those wires being pigtails to the three switches. A jumper between the 2 wirenuts.
You could just have 1 long pigtail as TK shows, and connect to the 3 switches. 2 wire nuts and a jumper was the main point.
In your Daisey Chain, I find it easier to go from the left to the right? Your Drawings are very good.

ABC, the one with one Greenie is exactly what is being done in the picture of the 3 gang box, and that picture is just some random picture I found on the net.

Elsewhere in the Code, equipment grounds only need to be counted as one conductor in a box when calculating wire fill of a box, since they all need to be combined, somehow.

The method of 3 Greenies, will fill the box quicker, and a deeper box will be needed. Electrically it is fine.

If a ground wire for a switch loop went to the one switch, and that cable went out to a single fixture, or fixtures, isolated,that cable going out to the fixtures would not be grounded, since it was not combined as required in a gang box.

IF all these cables were all EMT conduits, and since EMT conduit can be used as an equipment ground, no green or bare wire required, ALL the equipment grounds would be automatically connected by virtue of the connectors and locknuts at the gang box.

This exception stated in Mike Holt thread:

Exception: The equipment grounding conductor permitted in 250.146(D) shall not be required to be connected to the other equipment grounding conductors or to the box.,

Refers to the equipment ground of an Isolated Ground circuit, and allows it NOT to be combined with the system equipment grounding conductor, since an IG is intended to be just that, isolated.

Disregard any mention of Isolated Ground when dealing with residential. IG ground is only for special situations dictated by certain equipment, such as sensitive electronics, medical equipment, etc.



Keep in mind that Section 250.148 is for Continuity and Attachment of Equipment Grounding Conductors to Boxes. The first condition states that in all boxes all grounds get combined, and then A - E qualify how this connection shall be treated.

250.148 (D) is NOT an exception to the first paragraph of 250.148.

Since it refers to a plastic box, obviously the box does not need to be grounded, but re-iterates that each device in that box needs a connection to the equipment grounds.

If equipment grounding conductors are not combined or otherwise all connected together at each box, this action will violate the first paragraph of 250.148, and so many others in the Code, as equipment ground is common, and all connected, or bonded, together, at each location, box, etc.

All the grounds in a box connected together ensures they are all at the same potential, reducing a shock hazzard.