MC Cable in parallel

Status
Not open for further replies.
don_resqcapt19 said:
Try 300.3(B).
Click to expand...
OK... [I have a sneaking suspicion I've been down this path before :grin: ]

... but 300.3(B) states the EGC "shall be contained within the same raceway, ...cable tray, ...cable, or cord, unless..."

Please note the requirement uses the word "or". When you run paralleled MC in a cable tray, I'm of the impression you can run a separate EGC with them to meet the EGC requirement... because the EGC is within the same cable tray.

[My suspicion was correct... I found the last time I commented on the issue here.]

Edit to add... Click here to go directly to the appropriate bulletin and scroll halfway down to "Multiconductor Cables with EGCs in Cable Trays". Unfortunately, the bulletin is somewhat dated. I do not know if any changes have impacted that information and I do not have a NEC 1996 to reference.
 
Last edited:
Smart $ said:
OK... [I have a sneaking suspicion I've been down this path before :grin: ]

... but 300.3(B) states the EGC "shall be contained within the same raceway, ...cable tray, ...cable, or cord, unless..."
Click to expand...

I will agree that is a poorly written section.

If I was the inspector AHJ my interpretation would be that the conductors including the EGC be contained within the same metallic sheath.

But that is irrelevant to a technical guy like you. :D

Steve was not talking about the EGC being contained in the cable tray he was talking about using the cable tray as the EGC.
 
iwire said:
I will agree that is a poorly written section.

1.) If I was the inspector AHJ my interpretation would be that the conductors including the EGC be contained within the same metallic sheath.

2.) But that is irrelevant to a technical guy like you. :D

3.) Steve was not talking about the EGC being contained in the cable tray he was talking about using the cable tray as the EGC.
Click to expand...
1.) What would be your interpretation if it were a parallel run of plain ol' 3-conductor without ground tray cable?

2.) If you are to be the inspector, that would be quite relevant to me if I were in Steve's situation. But you are not, and I am not in Steve's situation :grin:

3.) I did not say anything about what Steve suggested. I was suggesting what seems to me to be a completely compliant alternative. Nonetheless, using the cable tray as an EGC is not totally out of the question, but it requires many considerations which I am not going to explore for the purpose of this discussion with you. As long as you maintain your position that the EGC(s) must be contaiined within the metal sheath(s) there is little point in doing so. Outside of code text and its interpretation, what reasons would you cite for contained, full-size EGC's to be required?
 
Thanks Iwire and everyone else for your input.

It still seems like I can use the cable tray as a ground if I don't use the ground conductors inside the MC cable.

It also seems like I could use the combination of the grounding conductor in the cable and the sheath to get a conductor large enough to comply.

But I'll take Iwires advice and ask the AHJ.

Steve
 
Status
Not open for further replies.
Top