Multiple grounds in the same raceway?

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Dr Duke

Dr Duke

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So a hypothetical situation:

Can you run more than one grounding conductor in the same raceway? Like 3 different circuits coming back to a common pipe? Would it be an NEC violation at all?

thanks
 
I've done it many times in certain situations where I thought it was better than splicing them all together and running just one of them back.
 
I suppose if you had several pipes entering a gutter and then nippling into a panel. Was just curious if anyone knew if it was a violation or not. I'm thinking not
 
But they all have to be sized based on highest rated overcurrent protection device Upstream. So you might end up with a couple 14 gauge conductors that have an 8 gauge ground.
 
petersonra said:
other than for some convenience, when would this ever be true?
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If you are routing the DC from two PV arrays into two inverters though a single conduit, you might want to run separate EGC's all the way to the inverters.
 
Just watch your conduit fill. Say for example you had plans that called for 3/4" EMT, nine 10awg current carrying conductors, and one 10awg ground. You'd be violating conduit fill if you ran another ground without upsizing the EMT to 1". But per se, no, it's not a violation.

Gutters and t-condulets are both situations where it's sometimes neater and cheaper to run more than one ground.
 
Dr Duke said:
So a hypothetical situation:

Can you run more than one grounding conductor in the same raceway? Like 3 different circuits coming back to a common pipe? Would it be an NEC violation at all?

thanks
Click to expand...

Pull as many as you like or as many as someone is paying you for. Personally more than one is usually a waste of someones money.
 
Question answered. The neatness factor is where it would come into play in my mind. Rather then placing a ground bar inside a gutter and then bring one ground into the panel. Either way, just a hypothetical question. Thanks for the responses.
 
petersonra said:
But they all have to be sized based on highest rated overcurrent protection device Upstream. So you might end up with a couple 14 gauge conductors that have an 8 gauge ground.
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The size is only based on the circuit that the EGC is associated with. It is not based on the other circuits in the raceway where you have an EGC for each circuit. If you have a single EGC for all of the circuits in the raceway, then it is based on the largest OCPD for those circuits.
 
don_resqcapt19 said:
The size is only based on the circuit that the EGC is associated with. It is not based on the other circuits in the raceway where you have an EGC for each circuit. If you have a single EGC for all of the circuits in the raceway, then it is based on the largest OCPD for those circuits.
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where does it say in the code that you can do this?
 
I believe that Don was referencing this:

250.122(C) Multiple Circuits. Where a single equipment grounding
conductor is run with multiple circuits in the same raceway,
cable, or cable tray, it shall be sized for the largest overcurrent
device protecting conductors in the raceway, cable, or cable
tray. Equipment grounding conductors installed in cable trays
shall meet the minimum requirements of 392.10(B)(1)(c).
Click to expand...
 
infinity said:
I believe that Don was referencing this:
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I was actually referring to his idea that you don't have to size the EGC for the largest OCPD of the conductors.

It seems to me that you cannot as a practical matter say that a specific EGC in a conduit only goes with a specific branch circuit.

Suppose you have 3 Bcs coming from the same panelboard with 3 separate EGCs. Unless the branch circuit wiring was in its own cable, I don't see how you can claim a specific EGC goes with a specific BC.
 
petersonra said:
I was actually referring to his idea that you don't have to size the EGC for the largest OCPD of the conductors.

It seems to me that you cannot as a practical matter say that a specific EGC in a conduit only goes with a specific branch circuit.

Suppose you have 3 Bcs coming from the same panelboard with 3 separate EGCs. Unless the branch circuit wiring was in its own cable, I don't see how you can claim a specific EGC goes with a specific BC.
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I don't see what's so difficult about it. If you have a t-condulet, or a pull box where one or more circuits has no splices, and/or the circuits exit through different hubs or knockouts, then it's obvious. It's only if all the conductors are spliced on both ends that I would be inclined to agree with you.
 
petersonra said:
I was actually referring to his idea that you don't have to size the EGC for the largest OCPD of the conductors.

It seems to me that you cannot as a practical matter say that a specific EGC in a conduit only goes with a specific branch circuit.

Suppose you have 3 Bcs coming from the same panelboard with 3 separate EGCs. Unless the branch circuit wiring was in its own cable, I don't see how you can claim a specific EGC goes with a specific BC.
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The same way as you identify the ungrounded and grounded conductors as part of a single circuit. I don't see any code rule that would require the individual EGCs to be larger than what is required for the circuit that they are associated with.
 
petersonra said:
Suppose you have 3 Bcs coming from the same panelboard with 3 separate EGCs. Unless the branch circuit wiring was in its own cable, I don't see how you can claim a specific EGC goes with a specific BC.
Click to expand...

I think you're reading more into the code than what's there, unless you have a code article I missed that states this?
 
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