Here is a very devisive issue - if several EGCs enter a distribution panel [or service panel], can you connect two or more of them together and pigtail a properly sized conductor to the EGC terminal bus? (e.g. 3 #12s enter the panel, you connect them together and run a #12 pigtail to the terminal).
The 2002 HEC Handbook 'commentary' for 250.122(C) says: "It [the EGC] is not required to be sized for the 'composite' of all the circuits in the raceway because it is not anticipated that all circuits will develop faults at the same time." - yes, this is a commentary on properly sizing the EGC in a j-box or conduit.
At issue: If you can size a single EGC to protect several circuits in a raceway or j-box, can you not do the same thing in the panel?
384-20 speaks of the requiring the grounding of panelboards, but it does not specifically address this question and I know of no other code section that does address this specifically.
The current language of 384-20 came into the code in 1990 and the 1990 NEC Handbook does not speak directly of this issue either.
BTW - this is NOT a practice I condone or support; however it is one of those 'code issues' I would like a clear and concise answer to. Opinions are great (mine is - don't do it), but the question is: Is there a particular code section prohibiting this practice?
Anyone have copies of the ROPs/ROCs for the 1990 code cycle?
Actually you have the code reference cited in your post. 99 NEC 384.20 & 2002 NEC 408.20 are the section to find it. The second sentence... Where the panelboard is used with nonmetallic raceway or cable or where separate grounding conductors are provided, a terminal bar for the grounding conductors shall be secured inside the cabinet.
This is telling you to terminate the EGC at the terminal bar. The NEC and the UL White Book both stipulate that if the terninal bar is not listed for more than 1 conductor in a terminal, than all conductors shall be individually terminated.
250.122(C) does not specify splicing multiple conductors, but says if you run MULTIPLE CIRCUITS, you can use '1' EGC in the raceway or cable as long as it is sized to the largest overcurrent protective device of the largest circuit in that raceway or cable.
Splicing all the EGC in a junction box is not a recomended practice if they are of different circuits.
I hope this helps
Re: EGCs - Proper Terimation in Panel#85235 06/12/0305:40 PM06/12/0305:40 PM
408.20 requires the equipment grounding bus, and 110.3(B) tells us that lissted equipment shall be used as per any instructions in the listing. That means one wire per terminal unless two per terminal are permitted. No bundling of all equipment grounding conductors in a panelboard. Creighton
Re: EGCs - Proper Terimation in Panel#85237 06/13/0302:41 PM06/13/0302:41 PM
408.20 requires the equipment grounding bus, and 110.3(B) tells us that listed equipment shall be used as per any instructions in the listing. That means one wire per terminal unless two per terminal are permitted. No bundling of all equipment grounding conductors in a panelboard. Creighton
Thank you Creighton!! I hope this settles this question that also asked in other areas on the net, and as stated the answer can be found in the reference that you quoted!
Joe Tedesco, NEC Consultant
Re: EGCs - Proper Terimation in Panel#85239 06/14/0305:51 AM06/14/0305:51 AM
I do respect what everyone here has to say, so I am going to ask you a favor. Read 250.148 again, I will post it here
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 separate equipment grounding conductors associated with those circuit conductors shall be spliced or joined within the box or to the box with devices suitable for the use...
...any separate equipment grounding conductors ASSOCIATED WITH THOSE CIRCUIT CONDUCTORS
Lets say there is a 6x6 jbox and we have multiple raceways (jbox and raceways are PVC) with multiple circuits. I am pulling an EGC with each circuit. I splice the EGC's of ONE CIRCUIT together(lets say those are 12 wire for receptacles). There is another 12 wire circuit(for lighting) in the same jbox, and I splice those associated conduuctors together and send them on their merry way. If I am reading this correctly, because they are not associated circuit conductors, and not associated circuits, I am not required to splice the EGC's of that circuit together with the other circuit EGC's. How big of a splice might that be if I had to, and how would I terminate such a large splice?
Thanks, let me know what you think,
Re: EGCs - Proper Terimation in Panel#85240 06/14/0306:54 AM06/14/0306:54 AM
Joe, I don't see any wording in the cited section that would prohibit this practice. It doesn't say that each EGC must be directly connected to an equipment grounding terminal. I don't like this idea, but still don't see any code rule that will prevent it. Don
Re: EGCs - Proper Terimation in Panel#85242 06/14/0303:12 PM06/14/0303:12 PM
This is good, we can hash this out, and be able to help each other out here.
About the exception: I believe this exception is trying to deal with 250.148, in a sense as to the extent that the IG is not required to be connected to the EGC, for obvious reasons, that I know you know.(that was hard for me to put in words, if it does not make sense to you, I will try to put it in other words, let me know)
I am not at all against using a ground bar, in a large enough jbox, and actually have, if you do want to connect them all together. BTW - I am not against connecting All the EGC together, I just do not think this section is making it required.
I also run 1 EGC in a raceway sometimes when the bidding process makes that necessary, But... if I can I like to run individual EGC's
In a metal residential switch box I would probably splice them all together, only because there probably will not be too many.
Not trying to be a pain, but answering how I would do it, so as to see what you would do.