Cable Selection

[jim gerlach]

I am trying to locate a cable/conductor that I can use for connecting motors from the local disconnect to the motor junction box that is highly flexible. Is there any conductor listed that has class G, W, or K stranding that I could use for both ease of installation, connection and flexibility? The conductors will be installed in sealtite.

I am using this for larger motors especially, eg. 25-200hp. Where the cable pull becomes especially hard due to large wires, and being pulled in a 'U' shape from disconnect to motor. Having read the article on cords it seems that I cannot use those listed. Primarily because it is hard to come up with ampacity and it is not listed for use in conduit. "Locomotive" cable is not therein listed nor "welding cable". Even if I go to a cable manufacturer and find something, will it meet design for 310-16 sizing, insulation type, etc.

Thanks for the input so far.

[ September 03, 2003, 03:16 PM: Message edited by: jim gerlach ]

 

[joe tedesco]

Re: Cable Selection

Types G and W are found in Table 400.4 and K was not there.

See the Table Note 4. Types G, G-GC, S, SC, SCE, SCT, SE, SEO, SEOO, SO, SOO, ST, STO, STOO, PPE, and W shall be permitted for use on theater stages, in garages, and elsewhere where flexible cords are permitted by this Code.

I wondered if 430.145(B) could be of any value to you since it covers a similiar type of installation.

Are you wiring some sort of Industrial Machinery? If so, see NFPA 79 where there may be rules that would help you to complete your design.

 

[tony_psuee]

Re: Cable Selection

Jim,

What size are the conductors required for the motors? I have used higher strand THWN wire, I believe 19 strands per conductor and welding cable. However, all require pulling three motor wires plus the EGC.

Tony

 

[don_resqcapt19]

Re: Cable Selection

Tony,
Welding cable is not listed for use as a power conductor.
Don

 

[ron]

Re: Cable Selection

Is "locomotive" cable an option. I do not know its technical name.

 

[flightline]

Re: Cable Selection

DLO or Diesel Locomotive Cable may be dual rated as DLO/RHH/RHW. This link will take you to the General Cable website and page for this product. There is also type "W" which may be suitable.

I hope it helps.

Gregg

[ September 03, 2003, 04:21 PM: Message edited by: flightline ]

 

[dereckbc]

Re: Cable Selection

DLO cable can be purchased as dual rated. I use it a lot for battery plant applications. American Insulated Wire manufactures several flexible cables with RHH/RHW-2 check http://www.aiwc.com/catalogsection/prodsdisplay.htm

Dereck

 

[dereckbc]

Re: Cable Selection

There is another manufacture called Cobra that makes several flexible cable types. The problem with DLO is it has a thick soft rubber insulation that makes it impossible to run in raceways.

You might check out this link and browse around http://www.cobrawire.com/copflex.html or http://www.cobrawire.com/products.html Most of the cables are RHH/RHW-LS with a cross-linked polyethylene composite thermoset. It is much thinner and slick. Easy pulling.

[ September 03, 2003, 05:22 PM: Message edited by: dereckbc ]

 

[don_resqcapt19]

Re: Cable Selection

dereck,
We have used DLO/RHW many times in raceways without any problems. Most of the time we use it for the armature feeds for large (1000 hp+) DC motors. The armature voltage is often 750 volts preventing the use of normal building wire with a 600 volt rating. The last motor we did was 1500 hp and there were four 4" conduits each with four 535.3 kcmil DLO cables. The runs were about 150' and we had no problem with the installation. The flexibility of DLO sure makes the terminations at the DC drive and the motor junction box a lot easier.
Don

 

[dereckbc]

Re: Cable Selection

Don I stand corrected. I personally never pulled it. I just have to listen to the contractors complain about it when I spec it out.

I mainly use it for DC plants and the cable is installed on cable ladder. There I have installed it and found it difficult to slide as compared to a cross-linked polyethylene.

I assume you are using cable soap??

 

[don_resqcapt19]

Re: Cable Selection

Dereck,
Yes, we use wire pulling lubricant and a tugger, but we would do the same for 500 kcmil THWN. We might use a little more lube with the DLO, but did not have any problems pulling it. It will not slide against itself very easily unless each conductor is completely covered with the lube, but we didn't have to slide it against other conductors as the group of 4 DLOs and the EGC were pulled at the same time.
Don

 

[dereckbc]

Re: Cable Selection

Don that is what I thought. When we use it for DC distrubution on cable ladder we may install 120 500 MCM on a cabble rack and therby we have to slide them against each other. Lube is not an option.

THX

Dereck