Bonding of Sleeves

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charlie b

charlie b

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There is a set of metal sleeves in the concrete slab between the first and second floors. Conduits containing communication wires will be passed through the sleeves. Fireproofing material will be installed in the gap between the outside of the conduits and the inside of the sleeves.

Is there a requirement to bond the sleeves? Would the answer be different if the conduits contained power wires (e.g., 277 volt lighting circuits)?

I looked in articles 250, 645, and 800, and found no answers. Is this really going to boil down to the opinion of the AHJ regarding whether the sleeves are ?likely to become energized??
 
charlie b said:
Is this really going to boil down to the opinion of the AHJ regarding whether the sleeves are ?likely to become energized??
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I guess it would. I agree there is no reference. I think the AHJ is stabbing in the dark if he(or she)has the opinion that they may become energized. Why even install sleeves if conduit is to be used? Interpretation could be different if line voltage involved!?
 
I should clarify that the AHJ is not (yet) a player in this discussion. Our design (drawings and specs) did not require bonding the sleeves. The EC has sent us an RFI. The RFI says that in their previous experience, the sleeves are to be bonded, and asks whether that is what we (the engineers) want them to do.

I was not involved in the design, so I don't know whether this had come up. I also don't know why there are conduits within sleeves. But my inclination is to say that bonding is not required. I just wanted to see if there is a relevant code article that I had missed during my review of the RFI.
 
Thanks, Chris. I note that that article tells me I don?t have to connect the sleeves to planet Earth (i.e., grounding). But I think the question asked by the RFI is do I have to connect the sleeves to other non-current-carrying metal objects that are likely to become energized, so that the collective set of metal is capable of carrying the fault current back to the source and trip the breaker (i.e., bonding)?
 
I do not see a sleeve as a system(s) as 250.104 refers to, I would not consider this installation as likely to become energized(as referenced earlier in thread).
 
Bonding of Sleeves

Sleeves in my opinion are not required to be grounded (bonded). The way we address this issue is by requiring electrical sleeves to be PVC, this resolve any question.
 
I don't see how the sleeves could be considered "likely to become energized" either. What would be the source? The conduit itself? What protects the rest of the world from conduit?
 
charlie b said:
Thanks, Chris. I note that that article tells me I don?t have to connect the sleeves to planet Earth (i.e., grounding). But I think the question asked by the RFI is do I have to connect the sleeves to other non-current-carrying metal objects that are likely to become energized, so that the collective set of metal is capable of carrying the fault current back to the source and trip the breaker (i.e., bonding)?
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Charlie, for what it's worth, here is 250.86 exception 2 from the ROP draft, after the task group went after the 'grounding/bonding' confusion:

Exception No. 2: Short sections of metal enclosures or raceways used to provide support or protection of cable assemblies from physical damage shall not be required to be connected to the equipment grounding conductor.
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I don't know what "the" EGC is, but your sleeves will not need to be attached to it if the term that currently reads as "grounded" is interpreted in the sense that I believe it to be intended, as actually bonded.
 
georgestolz said:
Charlie, for what it's worth, here is 250.86 exception 2 from the ROP draft, after the task group went after the 'grounding/bonding' confusion:



I don't know what "the" EGC is, but your sleeves will not need to be attached to it if the term that currently reads as "grounded" is interpreted in the sense that I believe it to be intended, as actually bonded.
Click to expand...

For what it is worth, this is how I felt this section was intended to be read as well. I know that the section states "Grounded" but it was my feeling that the intent was that short sections of raceways need not be bonded.

Chris
 
Many thanks, everyone. We responded to the contractor's RFI by saying that bonding is not required.
 
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