Can Unistrut be classified as a cable tray

[spencerodom]

My question is this, can standard 1 5/8” unistrut (Unistrut P1000T) be classified specifically as cable tray Under article 392, and not a strut type raceway as listed in 384?

I have a vendor that is trying to use slotted strut ascable tray for routing 6 triad 16awg control cables and 1 single pair 16awg. The full calculation comes out at 40.6% and he believes he is covered under 392.22 allowing 50% fill rather than the 40% fill and cover requirements for 384 raceway designation

 

[petersonra]

Short answer is it not a 392 raceway. Probably not 384 either as I think only solid strut is listed as raceway, and not all the solid stuff is.

These would seem to be either class 1 or 2 circuits. Might want to check article 725 and see if there is some wiggle room. Might be some if they class 2 circuits, but I think there is no wiggle room for class 1 circuits. I think he is out of luck entirely if they are class 1.

 

[tom baker]

The listing (classification) of a product is done by the manufacturer, not the end user. Seems like an expensive way to run a few control cables, why not a wire basket tray?

 

[paulengr]

Why not run type TC-ER? Then the strut becomes support, not tray. No more fill rule! As exposed run as long as it is supported every 3 feet it is legal whether in or out of tray. Lots of TC-ER never gets used in trays. Also there are some similar HL instrument cable designations. MC too if you want to mess with it. You can leave it in the strut or flip the strut over and run it on the back. Finally there is “tubing tray” which is typically 6” wide tray made by bending aluminum into a flat channel. It is so cheap the strut is probably more expensive, and can span much wider between supports.

Finally EMT is awful cheap.

 

[petersonra]

The listing (classification) of a product is done by the manufacturer, not the end user. Seems like an expensive way to run a few control cables, why not a wire basket tray?

Listing is done by an nrtl like ul.

 

[infinity]

Short answer is it not a 392 raceway. Probably not 384 either as I think only solid strut is listed as raceway, and not all the solid stuff is.

I agree but I don't see why there is a problem. Article 384 strut style raceways come in sizes large than just a standard 1 5/8 unistrut. Just use a larger size to increase the cross sectional area of the raceway.

 

[tom baker]

Listing is done by an nrtl like ul.

What I meant was a mfg product is made to comply with a listing. The end user installs per the listing

 

[don_resqcapt19]

I don't believe the slotted type is ever listed for use as a raceway. However, those cables may not be required to be in a raceway and if they are not, the strut is just being used as a cable support. There are no fill requirements for cable supports.

 

[electrofelon]

I don't believe the slotted type is ever listed for use as a raceway. However, those cables may not be required to be in a raceway and if they are not, the strut is just being used as a cable support. There are no fill requirements for cable supports.

We were working in large rooftop pv system and we needed to cross some walkways with PV wire. I suggested using unistrut on durablocks and just laying the conductors in it. In some cases there was hundreds of feet on each end so being able to lay the PV wire in would be a huge labor saver.. idea got nixed and we had to pull thru short emt sleeves - with raintight connectors on both ends

 

[suemarkp]

Our Facilities engineers tried to do the same thing. I said I needed a path for maybe 6 LV cables and they said use the unistrut that was going to be there already. I never thought of doing that... but said I'd rather have a skinny cable tray as I don't know what size of connetors we are going to be using or they may decide they want LMR-600 coax which is a fat thing to be stuffing in unistrut. For what Cooper B-Line charges for their tray, tray accessories, clamps, etc, strut is probably cheaper.

 

[gadfly56]

Here is what Unistrut has to say about their product:

"The Unistrut Metal Framing System includes an exclusive
combination of channel, fittings and hardware listed under
new UL classification 5B. This classification covers strut-type
channel raceways and fittings for use in accordance with
Article 384 of the National Electrical Code, NFPA 70. Included
are metal strut-type channel raceways at least .071
inch (1.81mm) thick and metal or non-metal closure strips
at least .040 inch (1.02mm) thick."