Type W cable versus welding cable

[ridge]

WE are installing cam locks for Television production trucks and theatre light set ups. We need something flexible to run from the 200 amp disconnect to the back of the cam locks. The cam lock enclosure is at the most 2 feet from the disconnect. The conductors are in conduit. We have been running 4/0 welding cable. We were told by our new EE that we could not run welding cable, we had to run Type W cable. The book for the welding cable says it is good for more current even in conduit than the Type W cable. The welding cable is Carol Super VU-Tron Welding Cable-Extra-Flexible (UL)600 Volts (-50C +90C) Oil Resistant P-123-141-MSHA 4/0 AWG Arc Welding Cable FT1. The type W says Carol Super Vu-Tron Type W Portable Power Cable (UL) Dry 90C Wet 75C 2000 volts Sunlight resistant P-123-MSHA 4/0 AWG Type RHH or RHW(UL) 600 Volt. Can you tell me what is right and what Code Articles pertain to this?
Thanks for your help

 

[ryan_618]

Re: Type W cable versus welding cable

When you say that it is in conduit, is it in PVC?

 

[tonyi]

Re: Type W cable versus welding cable

You may want to take a look at Articles 310 (conductors for general wiring) and 520 (theatres, studios and such)

The welding cable, although it may carry the amps, is going to have issues with the lugs on your disconnects. Fine stranded wire can work its way out of the lugs. Welding cable is for welding applications, not general wiring.

 

[don_resqcapt19]

Re: Type W cable versus welding cable

Tonyi,
The Type W cable has the same stranding as welding cable. You must use terminations suitable for the type of conductor that you are using.
Don

 

[don_resqcapt19]

Re: Type W cable versus welding cable

ridge,
The use of welding cable for power wiring is a code violation because welding cable is only listed for use on the secondary side of electric welding machines. The quote below is from the UL Guide for welding cable (ZMAY).

This category covers welding cable which is a single-conductor cable inended for use in the secondary circuit of electric welders in accordance with Article 630, Part IV of NFPA 70, "National Electrical Code."

While welding cable has often been successfully used for portable or temporary power applications, its use is always a code violation because of the listing. I've been told that there is a manufacturer who has dual listed cables that can be used for both welding and power applications. I have not seen this cable and do not know who is the manufacturer.
Don

 

[dereckbc]

Re: Type W cable versus welding cable

Did I read RHH/RHW rating?

 

[tonyi]

Re: Type W cable versus welding cable

Originally posted by don_resqcapt19:
Tonyi,
The Type W cable has the same stranding as welding cable. You must use terminations suitable for the type of conductor that you are using.
Don

One of my points, perhaps not made clear enough, is that there is no welding cable listed in 310 for general wiring - hence its use, unless specifically dual listed as such, is gong to be an issue. The lugs comment is just a practical matter.

 

[don_resqcapt19]

Re: Type W cable versus welding cable

tonyi,

... is that there is no welding cable listed in 310 for general wiring ...

True, but some type W cable is physically identical to welding cable and the only difference is the listing. Type W cable is in Article 400.
Don