Connection of grounds in a quad non-metallic outlet box

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K1GMB

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I am installing four (4) individual hubble 20-amp surge arrestor outlets in a non-metallic outlet box. Each hubble surge arrestor outlet will be dedicated to a single Square D QO CAFI circuit breaker. There are individual runs of 12-2 from the electrical sub-panel to each surge arrestor. At the sub-panel, all grounds are connected to a separate grounding buss bar, connected back to the main electrical panel, AND a connection to a locally 8' driven copper electrode. Because of the CAFI, there are separate neutrals and hots for each surge arrestor receptacle. My question is, do I need to tie all grounding conductors together in the non-metallic outlet box? Electrically the #12 grounding conductor of each surge arrestor receptacle is a home run back to the ground buss bar in the sub-panel. Electrically there is a dedicated earth ground on each circuit. In researching Article #250, (2020 NEC edition), I found section 250.140 (D) that seems to address my question. I really don't want to have to tie up space in this quad outlet box unless I absolutely have to. Thanks!!!!!
 
ptonsparky said:
That is the local rod. It is something else. CNC machines would ask for ground rods at the machine. Fine, allowed as long as an EG is there and used.
Motormuff beat me.
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You know what member 'GAR' would say about machine grounding.
I believe that in most cases that an added ground rod at a CNC machine is next to useless, and probably a problem.

BETATRONICS&reg, RS232 Noise and Grounding Information, I232, upload, download, vendor, supplier, manufacturer, industrial

A discussion on Noise and Grounding relative to RS232 and CNC machines. Need for Electrical Isolation.
www.beta-a2.com
 
Ok so this is one of those posts where we have the initial posts and then nothing else from the OP. I will message him
 
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ptonsparky said:
IMO, the rod just adds cost to the job & more profit for you as well, but then I don't understand why you are going to this effort for any of it.
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Bit more to the story. This is a personal home project, got the time, my money, do it right and in a manner that exceeds BASIC code requirements. Basically, electrical wiring/work that is within a high RF transmitting environment, so I want a good ground reference. Running the new CAFI's as per code in rooms where they mandate it, I want to try to minimize if not eliminate any potential problems with Radio Frequency interference.
Good grounding and shielding becomes a factor when you are also working and dealing with high power radio frequency energy.
 
K1GMB said:
Good grounding and shielding becomes a factor when you are also working and dealing with high power radio frequency energy.
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Seems to me best practices with a high EM interference environment, will move sensitive AFCI and GFCI electronics behind home-run impedance, per 210.12(A)(5), and plan for readily accessible outlet locations, per 210.12 & 210.8.
 
So I've read the OP four times and all the post twice. I still don't see an answer to the OP's question. It's kind of like the diesel forum in here....someone says squirrel and we all loose our minds. LMAO

The original question, and correct me if I'm wrong, is "do I need to tie all grounding conductors together in the non-metallic outlet box?" Meaning, since each device in the box has a separate home run, and each gnd is seamless back to the panel, does each device need to be grounded together since the box is non-metallic. It would be a lot cleaner in the box if it there were all separate. I'm curious as to ya'll answers as I'm not just fluent yet in the code book.

EDIT: I guess this is most likely a commercial or industrial application but what I had envisioned in my mind was NM with bares. I'm assuming in com/ind you'd have conduit and only run one grounding conduction and splice them all together in the box. Maybe that's where I missed the answer. But the way it was worded, each run has it's own gnd.
 
No.
4x4dually said:
So I've read the OP four times and all the post twice. I still don't see an answer to the OP's question. It's kind of like the diesel forum in here....someone says squirrel and we all loose our minds. LMAO

The original question, and correct me if I'm wrong, is "do I need to tie all grounding conductors together in the non-metallic outlet box?" Meaning, since each device in the box has a separate home run, and each gnd is seamless back to the panel, does each device need to be grounded together since the box is non-metallic. It would be a lot cleaner in the box if it there were all separate. I'm curious as to ya'll answers as I'm not just fluent yet in the code book.

EDIT: I guess this is most likely a commercial or industrial application but what I had envisioned in my mind was NM with bares. I'm assuming in com/ind you'd have conduit and only run one grounding conduction and splice them all together in the box. Maybe that's where I missed the answer. But the way it was worded, each run has it's own gnd.
Click to expand...
NM cable, AFCI, and 'personal home project' would indicate a residence to me, but I've done a lot of stuff at home before moving it out to the field.

eta: I never did find 250.140 (D)
 
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ptonsparky said:
No.

NM cable, AFCI, and 'personal home project' would indicate a residence to me, but I've done a lot of stuff at home before moving it out to the field.

eta: I never did find 250.140 (D)
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Ah...yes. The "12-2" should have gave it away to me it was NM. That went right past me every time I read it. This is why my reading comprehension ACT score was the lowest. LOL
 
4x4dually said:
So I've read the OP four times and all the post twice. I still don't see an answer to the OP's question. It's kind of like the diesel forum in here....someone says squirrel and we all loose our minds. LMAO

The original question, and correct me if I'm wrong, is "do I need to tie all grounding conductors together in the non-metallic outlet box?" Meaning, since each device in the box has a separate home run, and each gnd is seamless back to the panel, does each device need to be grounded together since the box is non-metallic. It would be a lot cleaner in the box if it there were all separate. I'm curious as to ya'll answers as I'm not just fluent yet in the code book.

EDIT: I guess this is most likely a commercial or industrial application but what I had envisioned in my mind was NM with bares. I'm assuming in com/ind you'd have conduit and only run one grounding conduction and splice them all together in the box. Maybe that's where I missed the answer. But the way it was worded, each run has it's own gnd.
Click to expand...
Thanks, you are right on target!! I didn't think that my question was that difficult, but as with many posts there are always people that are smart asses and attempt to make themselves out to be smart by their obnoxious answers. Yes, no answers or comments on the original question! My concern was by connecting all the grounds together at the "destination" (LOAD side), this was possibly creating a "ground loop" situation. These newer technology arc fault circuit breakers seem to be moderately to severely sensitive. Henceforth the need to isolate neutrals from stray currents of other circuits that may terminate in the same electrical box. I was attempting to carry this concern over to the grounding conductor for thoughts. But I didn't get any thought respectable answers, or provoking comments to help me decide how I was going to proceed. So, I used the newer (UL listed) plug in tap cubes to connect all four (4) incoming grounds, and the four (4) outgoing pigtails to the dedicated surge arrestor receptacles in a non-metallic PVC box. It makes for a "busier" box with all of the various grounds, and I'm not sure if all of that is needed. All circuits are individual homerun (NM) and have their own dedicated CAFI. --Whatever-- It's completed. Extensive testing all these new circuits with the newer CAFI's in the near proximity of a 1 kW (that's 1,000 watts to those un-educated), did not show any signs of radio frequency interference issues.

Thank you for your "kind" and accurate observation.
 
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