Using Structural HSS as a Raceway

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mpcarnahan

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Working on a canopy made with hollow strucutral steel 6" x 8". Trying to bring a circuit up through the base plate with 1-1/2" PVC. Then run the wires up to a jb on top of the canopy.
Q: does the hollow structural steel have to be UL Listed as a raceway in order to do this? Or can I just pull the wires through?
If it does, then what?

signed,
stuck-in-a-ditch
 
mpcarnahan said:
Working on a canopy made with hollow strucutral steel 6" x 8". Trying to bring a circuit up through the base plate with 1-1/2" PVC. Then run the wires up to a jb on top of the canopy.
Q: does the hollow structural steel have to be UL Listed as a raceway in order to do this? Or can I just pull the wires through?
If it does, then what?

signed,
stuck-in-a-ditch
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If the steel is not being relied on as part of the EGC and the wiring type being used does not require a raceway, then the steel is simply another enclosure or space through which the wire is run, rather than being a raceway.

However, if the part in question is actually used either structurally or as part of the building finish (considering the canopy as a free standing building or part of another building) then the space would be considered "concealed" and the type of wire you could put into it would be limited by that. Any wiring type that could be run concealed without using a raceway, and suitable for the temperature and moisture conditions existing inside the steel would be OK, IMO.
 
GoldDigger said:
If the steel is not being relied on as part of the EGC and the wiring type being used does not require a raceway, then the steel is simply another enclosure or space through which the wire is run, rather than being a raceway.

However, if the part in question is actually used either structurally or as part of the building finish (considering the canopy as a free standing building or part of another building) then the space would be considered "concealed" and the type of wire you could put into it would be limited by that. Any wiring type that could be run concealed without using a raceway, and suitable for the temperature and moisture conditions existing inside the steel would be OK, IMO.
Click to expand...

Wiring type is a (2) 2/0 thhn. coming from a PVC stub up in the HSS.
 
It would be a violation, THHN is required to be run in a chapter 3 wiring method. The steel is not a wiring method.

You will need to put some sort of raceway inside the steel or switch to some sort of cable.
 
mpcarnahan said:
Working on a canopy made with hollow strucutral steel 6" x 8". Trying to bring a circuit up through the base plate with 1-1/2" PVC. Then run the wires up to a jb on top of the canopy.
Q: does the hollow structural steel have to be UL Listed as a raceway in order to do this? Or can I just pull the wires through?
If it does, then what?

signed,
stuck-in-a-ditch
Click to expand...
I think you will need to run it inside cable or conduit within the HSS.
 
Way back when I was a little kid daddy told me to never use water pipe for conduit, as the water pipe can have sharp internal weld edges that will cut wire insulation*.


SAME is true for structural tubing welds, so use as raceway unless listed for electrical use, even if one can weasel word code, is not advisable.


* Daddy, being a practical old deutchman, did say that OLD water pipe that you have to knock the rust out of would be OK, as the rust has taken all the sharp edges off.
Pretty sure NEC does not allow old water pipe or rusted structural tubing for conduit <G>
 
We do highway lighting controls and when I'm out on a highway near aluminum light poles, it sounds like I'm in a marina on a windy day. The conductors are slapping the inside wall of the aluminum pole as it sways. One day there will be fireworks in there after enough slapping. And no ground; two wire system!
 
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