supporting wire at lugs

[sokkerdude]

We are installing a 3000 amp transfer switch. With a pull section that has the lugs for the normal, load , and generator extending of the respective buses on one side of this pull section. There is 8 set (4-500 mcm) coming out of the slab for normal power. There is 8 set (4-500) coming out of the top for load. And 4 set (4-500 mcm) out of slab from generator. The owner is wanting each 500 mcm supported before being landed on a lug. He has built a rack inside the pull section to support the 500 mcm at 14 in. in front of the lugs. I can't find in code reference about needing to support the conductors. Am I missing something. Any information would help. His rack is limiting the bending radius of the 500's . Thank you

 

[George Stolz]

He has built a rack inside the pull section to support the 500 mcm at 14 in. in front of the lugs.

That could be argued as modifying listed equipment, 110.3(B).

I can't find in code reference about needing to support the conductors. Am I missing something. Any information would help.

The closest thing I can find is 314.28(B) - but given that this is a transfer switch and not a pull/junction box, I don't believe it would have to comply with that section.

His rack is limiting the bending radius of the 500's . Thank you

I would say, get it out of there so you can do your job, and let the owner stick to owning.

 

[don_resqcapt19]

Check the installation instructions for the transfer switch. A lot of equipment of that size requires the "lacing" of the conductors with 3/8" nylon rope to prevnet excessive movement under fault conditions.
Don

 

[Gmack]

300.19 Supporting Conductors in Vertical Raceways

300.19 Supporting Conductors in Vertical Raceways

.

IMO the O has a legit concern and 300.19 does apply to raceways and conductors without regard to the TS.

Having said that I would agree with George that the "rack" is "iffy". What method would be employed to fasten/support conductors to it.

I would do my own RFI with the AHJ before losing money in a conflict with the O.

 

[celtic]

That could be argued as modifying listed equipment, 110.3(B).

I would think the better arguement for 110.3(B) is :

....equipment shall be installed and used in accordance with any instructions included in the listing or labeling.

Many pieces of gear we install state in the instructions that the terminal/lugs are NOT to be relied upon as support for conductors.

 

[celtic]

He has built a rack inside the pull section to support the 500 mcm at 14 in. in front of the lugs. I can't find in code reference about needing to support the conductors. Am I missing something. Any information would help. His rack is limiting the bending radius of the 500's . Thank you

The rack may need relocating or "beefing" up.

We typically use 1 5/8" kindorf or 3/4" EMT/RMC (whichever is available).

The rack can be installed after pulling and terminations to facilitate those tasks.

 

[crankshaft]

cable ties, rope, nonconductive kindorf, threaded rod sleeved inside pvc or rod wrapped with ruber pads, ty rap right to the sides inside the gear with edge guard, heavy duty sticky backs with cable ties, rope with insulating poreclains or victor splits, i could porbably write a book on how to support cable in gear. just use common sense along with nonconductive material. thomas and bettes makes mayn products and types of ties with mounting cradles

 

[infinity]

Check the installation instructions for the transfer switch. A lot of equipment of that size requires the "lacing" of the conductors with 3/8" nylon rope to prevnet excessive movement under fault conditions.
Don

Don is correct. I have seen a good deal of equipment that required bracing or lashing of conductors to prevent violent motion that may occur during a fault condition. There are many ways to do this. But if the method interferes with the required bending radius of the conductors than an alternate method should be employed.

 

[celtic]

cable ties, rope, nonconductive kindorf, threaded rod sleeved inside pvc or rod wrapped with ruber pads, ty rap right to the sides inside the gear with edge guard, heavy duty sticky backs with cable ties, rope with insulating poreclains or victor splits, i could porbably write a book on how to support cable in gear. just use common sense along with nonconductive material. thomas and bettes makes mayn products and types of ties with mounting cradles

How about ty-wrapping "standard" kindorf with the insulation from the 500's....the helpers are busy stripping the bunnies anyway