Wires in wooden light pole.

patrox2000

Member
Location
Baltimore, MD
Hello all,

A client wants wooden light poles for their parking lots. These poles have an internal 1” square cavity running the entire length of the pole, which the manufacturer says can be used to run wires to the fixture at the top of the pole. However, the manufacturer cannot confirm if this is acceptable per the NEC. Does the NEC allow running THHN wires inside wood poles? Or do I have to insert a PVC conduit in this cavity? Or maybe run liquid-tight FMC inside? Please provide an NEC reference to back up your answer.

Thanks.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
Individual condcutors need to be in a raceway or a cable and a wood chase is neither. {300.3(A)}
 

kwired

Electron manager
Location
NE Nebraska
Just pull a cable wiring method through that chase. May or may not be deemed a wet location in there. UF cable works either way.

Question: how do you access that lower end of that chase? Metal poles (over certain height anyway) are required to have a handhole near the base to access the conductors.
 

patrox2000

Member
Location
Baltimore, MD
Question: how do you access that lower end of that chase? Metal poles (over certain height anyway) are required to have a handhole near the base to access the conductors.
THHN conductors in PVC conduit will come in through the base of the pole, as with any other pole, and up to an external junction box on the side of the pole. The junction box will be about 1'-6" above the ground. When you say required, do you mean by the NEC?
 

steve66

Senior Member
410.30 (B) Metal or nonmetallic poles shall be permitted to be used to support luminaires and as a raceway...
 

kwired

Electron manager
Location
NE Nebraska
THHN conductors in PVC conduit will come in through the base of the pole, as with any other pole, and up to an external junction box on the side of the pole. The junction box will be about 1'-6" above the ground. When you say required, do you mean by the NEC?
410.30 steve66 mentioned has the handhole requirements also.

410.30 (B) Metal or nonmetallic poles shall be permitted to be used to support luminaires and as a raceway...
I guess wood is nonmetallic.
 

steve66

Senior Member
If is is listed that way then I think you can run individual conductors such as THWN. Still also have the handhole requirement unless you meet exceptions or have some listing that says otherwise.
Yes, there is also the handhole requirement. The OP did say the pole had a handhole, but he didn't say what size it was.

To me, 410.30B says a pole does not need a listing to be used as a raceway. Even when I look at cut sheets for metal poles, I don't usually see any listing for use as a raceway mentioned (although a pole may have an option for a UL listing and sticker, its not a common thing to include)

And, yes, wood is obviously non-metal, so IMO, single conductors are OK if the handhole is sized correctly.
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
THHN conductors in PVC conduit will come in through the base of the pole, as with any other pole, and up to an external junction box on the side of the pole. The junction box will be about 1'-6" above the ground. When you say required, do you mean by the NEC?
Without seeing a cut sheet for the actual pole, from your description I have a problem with the conductors exiting the underground PVC going into the external junction box. It sounds like they will also be run exposed within the wooden chase for that 1'-6".

I would like to see the PVC connect directly to the JB outside the pole, then UF out the back of the JB with a suitable connector into the pole chase. This still leaves the question of how to terminate the UF at the top- it needs a connector unless the fixture is designed for it.

-Hal
 

steve66

Senior Member
Without seeing a cut sheet for the actual pole, from your description I have a problem with the conductors exiting the underground PVC going into the external junction box. It sounds like they will also be run exposed within the wooden chase for that 1'-6".


-Hal
I don't see the problem:

410.30 (B) Metal or nonmetallic poles shall be permitted to be used to support luminaires and as a raceway...
:?
 

steve66

Senior Member
The Code needs to define "nonmetallic". I take it to mean plastic or composite, not wood.

-Hal
Since there is no specific definition in the code for nonmetallic, we are supposed to use the standard dictionary definition.

[h=3]not containing or resembling or characteristic of a metal[/h]
I don't see how that doesn't include wood. If the code authors didn't want to include wood poles, I think they would have specifically excluded wood.
 

tkb

Senior Member
Location
MA
Since there is no specific definition in the code for nonmetallic, we are supposed to use the standard dictionary definition.

not containing or resembling or characteristic of a metal


I don't see how that doesn't include wood. If the code authors didn't want to include wood poles, I think they would have specifically excluded wood.
Wood poles have been used for lighting ever since Thomas Alva started wiring them.
 
Top