4 wire 4 condcutor cord

[WLB]

I am trying to find 4 wire cord rated for at least 125 amps and the SOOW cord in the NEC lists it at 85 amps, can someone point me in the right direction?

 

[jumper]

What is the application?

 

[WLB]

Industrial Machine Cabinet

Industrial Machine Cabinet

We have 3 each 15 HP 3 phase motors, 4 each 4 HP 3 phase motors, 1 each VFD 5.7 amp input max rating and a 1500 VA 480/120 transformer.
I figured 1.25 x 21 = 26.25 +(2x21) + (4.8 x 4) + 5.7 + (1500/480) = 96.275 x 1.25 = 120.35 amps drop cord feeding the disconnect.
409 Industrial Control Panels Part II. Installation 409.20 Conductor - Minimum Size Ampacity

 

[zbang]

I don't think I've seen S-type cable over 2g and you really don't want to move that stuff, it's heavy. Can you use single-conductor SC-type and tie/band them together? With SC, you might be able to use 4AWG (140 amp) if the terminations will allow it (check 400.5(A)(2)). Oh, and you need to use terminals rated for fine-strand cable, but they're not hard to find.

Of course, other factors may apply .

 

[WLB]

I had not thought about SC cable, this is a cord drop from the ceiling we just have always used SOOW cords. I suppose I could use the individual SC Cables and but since they can't come in contact with each other (Table 400.5A(2) Note 1 temperature rating of cable (167 deg. F) Column D note 1. I can't even spiral wrap them, not sure what a clean way would be to drop 3 individual conductors + Ground.

 

[Frank DuVal]

You are now in the area of big cords, Type W and Type G-GC.

We use 2/0 Type W and 2/0 G-GC a lot here. Yes, very heavy!!!!!!

 

[zbang]

I suppose I could use the individual SC Cables and but since they can't come in contact with each other (Table 400.5A(2) Note 1 temperature rating of cable (167 deg. F) Column D note 1.

Sure they can, skip over Note 1 and derate a bit. Even if you go to col F @ 75 deg, you get 133 amps on 2g.

It also looks like you've got the 1.25 factor in there twice. Take a look at 409.20 again-

an ampacity not less than 125 percent of the full-load current rating of all resistance heating loads plus 125 per-cent of the full-load current rating of the highest rated motor plus the sum of the full-load current ratings of all other connected motors and apparatus based on their duty cycle that may be in operation at the same time.

If you don't have any heaters, the first doesn't apply, and there's no multiplier on the total. You also get to take duty cycle into account.

 

[Jim1959]

I am trying to find 4 wire cord rated for at least 125 amps and the SOOW cord in the NEC lists it at 85 amps, can someone point me in the right direction?

Could you consider LFMC (Sealtite) with THHN CU conductors? Would give you more flexibility in selection of conductors. You would probably need a Kellums style grip at the top, and possibly support for the conductors. How long of a drop is it?

 

[WLB]

So I am applying that 409.20 wrong, if I do the amps over again and only multiply 1 of the 15 HP motors x 1.25 and just add the sum of the remaining it only comes to 89.98 amps and they are all in operation almost all the time.
The 90 amps is still above the SOOW cord table 400.5(A)(1) column A note a #2 AWG is only rated at 80 amps.

To have the flexibility of the SOOW cord can you recommend which type of cable to use for a 480 VAC 3 Phase drop feeding the disconnect on the machine cabinet ?

 

[Frank DuVal]

Sure I can, let me repeat my above post:

Type W and Type G-GC.

Frank DuVal

 

[zbang]

Or single conductor type SC. G-GC might be excessive for the purpose (don't need the ground check conductor). You probably don't need 2000 volt insulation, either. Anyway, do some research into these types and you'll find something.