Grounds with different size wire and ground wire nut

[penright]

I am running #10 and #12 in the same raceway. I have #10 ground. I assume I can use #12 ground to the duplex that is a wire with #12 load and neutral.
Questions:

1. what size do I have to use for the ground to the box?
2. Do they make green wire nuts that are big enough for a 3 #12 and 2 #10? If not, can you use a different color wire nut?
3. If I have to use #10 for the box ground, my #10 is stranded. How do you attach the stranded wire to the box? I know you would use the same screw, what I am asking is how solid wire would be pressed and stranded would run out from under the screw.

 

[alfredeneuman]

I am running #10 and #12 in the same raceway. I have #10 ground. I assume I can use #12 ground to the duplex that is a wire with #12 load and neutral.
Questions:
1. what size do I have to use for the ground to the box?
2. Do they make green wire nuts that are big enough for a 3 #12 and 2 #10? If not, can you use a different color wire nut?
3. If I have to use #10 for the box ground, my #10 is stranded. How do you attach the stranded wire to the box? I know you would use the same screw, what I am asking is how solid wire would be pressed and stranded would run out from under the screw.

1. #10
2. They don't make green wire nuts that big, and they aren't required. A regular grey or blue wire nut will do.
3. Use a crimp on ring tongue with a #10 hole in it and just use the ground screw as you would normally do.

 

[Bert_]

Use whatever wire it is rated to fit. I hardly ever use the green ones myself.

Use solid wire for all your pigtails. Works fine under all screws

 

[ard]

AFAIK, You can ground the outlet/device which is connected with #12 wires with a #12 jumper.

WHY are you using #10 for ground? Just because or is it actually required due to design considerations?

 

[penright]

AFAIK, You can ground the outlet/device which is connected with #12 wires with a #12 jumper.

WHY are you using #10 for ground? Just because or is it actually required due to design considerations?

I have a series of outlets along the top of the workbench. I included a picture to help. Please don't judge about the clutter.
At the end of the outlets is another JBox for the compressor connection. I ran #10 for that and it passes through the 3 outlet boxes. I used #12 for the duplex outlets circuit. My understanding for the #10 circuit I have to use #10 ground. I also understand for the outlets I only have to use #12. The grey area was the JBoxes. Since the outlets are #12 can I use #12 to the box or because #10 is passing through the box I have to use #10.

 

[sberry]

One of the advantages of pipe especially on all metal building is no ground wire needed.

 

[alfredeneuman]

One of the advantages of pipe especially on all metal building is no ground wire needed.

....but if you choose to do so it must be sized to the largest grounding conductor applicable to the circuits in the conduit, which is in this case is #10.

 

[ard]

....but if you choose to do so it must be sized to the largest grounding conductor applicable to the circuits in the conduit, which is in this case is #10.

Are you sure there is only one ground? Or is he running multiple grounds for the various 'circuits' he is running????

I ran #10 for that and it passes through the 3 outlet boxes. I used #12 for the duplex outlets circuit. My understanding for the #10 circuit I have to use #10 ground. I also understand for the outlets I only have to use #12.

]

 

[wyliesdiesels]

....but if you choose to do so it must be sized to the largest grounding conductor applicable to the circuits in the conduit, which is in this case is #10.

Huh?

Sberry is saying no ground wire is needed if metal conduit is used....

 

[alfredeneuman]

Huh?

Sberry is saying no ground wire is needed if metal conduit is used....

What part of "....but if you choose to do so" do you not understand?

 

[alfredeneuman]

Are you sure there is only one ground? Or is he running multiple grounds for the various 'circuits' he is running????

He said in his first post "I have #10 ground."

 

[ard]

He said in his first post "I have #10 ground."

but in a latter post (which I quoted) he added something about #12.


Lets see what OP says.

 

[alfredeneuman]

but in a latter post (which I quoted) he added something about #12. Lets see what OP says.

 

[penright]

Sorry about the confusion. I understood what @sberry was saying. Just after the building was built and I was getting ready to run electrical, I posed the question if I had to pull a ground with EMT. Of course, the answer was no, but it would not hurt. Just if you did pull a ground then you had to ground the boxes. I decided to go with the ground wire. Also, I was running into a box fill issue that I could have pulled the ground wire out and helped, but after adding the lid, I was in limits. Again, sorry I was not clear.

Back to this thread.
There are 3 circuits in that raceway. One is outlet power, the other is switched lights, and the third is the compressor. The outlet power and switched lights are #12. I actually had a #12 ground. Then when I pulled the #10 for the compressor, I pulled the #12 ground running from the distribution panel looped into each JBox and replaced it with a #10 ground. So, for now, I spliced the #12 that grounded the box and the outlets to the #10 ground. What I was asking if I need to replace the #12 going to the box with a #10.
There were more questions were answered. They were wire nut color and stranded wire to a screw were answered. Color does not matter (green) as long as the size is correct for that splice. If I need to replace the #10 ground to the box, then I need to get some solid #10 ground.

Again, sorry for the confusion.

 

[7635tools]

Solid wire ***** to begin with let alone 10 solid. Use stranded wire and fork stake on to the receptacle.


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[alfredeneuman]

What I was asking if I need to replace the #12 going to the box with a #10.

You only need 1 ground per conduit
If the box is grounded with a #12; as long as the #10 is present, (and you've got #10s for the active conductors) you need to switch it to a #10.

You could downsize the ground to a #12 if there are only #12s in the conduit and the boxes.

I hope that I understood this time.

 

[alfredeneuman]

Solid wire ***** to begin with let alone 10 solid. Use stranded wire and fork stake on to the receptacle.

As long as the receptacles are fed with #12s he could run #12s for the pigtails wirenutted to the #10.
Any receptacle designed for #10 (such as 30 amp) will accept a #10 ground wire

 

[mm08822]

Penright, since you did a good job of running the conduit and mounting boxes to the steel girts, I would forget the gnds. A lot of headache for very little gained.

The jumper to the recepts could even be eliminated b/c of using raised covers on surface mounted steel boxes. If you still want these, then make some #12 green jumpers with stakons and connect to jbox.

 

[penright]

as long as the #10 is present, (and you've got #10s for the active conductors) you need to switch it to a #10

I was betting that would be the case. Seems to me if current-carrying #10 shorted to the box then the ground would have to carry the current till the breaker tripped.

Any receptacle designed for #10 (such as 30 amp) will accept a #10 ground wire

Actually the compressor will be hardwired. I am using 3 conductor #10 SO cord. It is about 15' from the breaker and well within the 50'. There is a clear line of sight to the breaker. The compressor just wants the L1, L2, and ground. Without the ground wire I would have had to connect to the box, which is ok, just feel better with the ground wire.


The outlets and switched light circuits (#12) was existing before the compressor. I started to run a separate conduit. https://www.garagejournal.com/forum/showpost.php?p=8116056&postcount=6 Then I figured I can run it in the existing raceway. That is why #12 was there already and hence my changing of the grounds.


For here is more information that you care, here is the link for the entire "do I use existing raceway or new one/box fill" thread. https://www.garagejournal.com/forum/showthread.php?t=432765