DLO Cables

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dvcraven0522!

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Good Morning - I am designing cables for temporary full generator back up with cam-locks. I have attached a spec. sheet for DLO cabling. I don't know much about this type of cable but we apparently have used this on previous designs.

In essence I plan on a 600 amp service with a manual transfer switch for the generator. Per the attached spec. I am not sure in the columns for amps what is meant by 1 & 2.

As an example for #4/0 indicates 260amps for (1) and (405 for (2). I would assume 2 cables. Is that correct?

Thank you for taking the time to review my question.
 

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IMHO forget you've ever heard of "DLO", it's not an NEC type although it's often dual rated to RHW/etc.

The usual stuff for temp. distribution is type W (and occasionally SC) sized per table 404.5(A)(2). Beware of cable temperature vs termination temp- often the cable is rated for 90c and the other parts of the system at 75c; you're probably in the 75c column D for convenience.

Also, fine-strand cable needs lugs rated for it (the Camloks are), and I've seen a fair number of setups where the flex cord is rated/run at 90, then the source/destination ends use lugs&wire sized at 75c to get to the breakers.

You can both rent and buy pre-made camlok cables and distribution boxes, highly recommended.
 
In 40+ years I've never seen "type DLO" used for Camloks (or Tweco connectors)- we used to use welding cable then when types W and SC appeared everyone switched to those. Remember that "DLO" is a cable type which isn't in the NEC, do not use it as a general term for fine-strand flexible cord.

If you go to any of the large temp. power rental houses, you will get W, not "DLO".
 
zbang said:
In 40+ years I've never seen "type DLO" used for Camloks (or Tweco connectors)- we used to use welding cable then when types W and SC appeared everyone switched to those. Remember that "DLO" is a cable type which isn't in the NEC, do not use it as a general term for fine-strand flexible cord.

If you go to any of the large temp. power rental houses, you will get W, not "DLO".
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The reason is likely that DLO cable costs more than type W. But I agree with your basic assertion that few if any would use DLO for making up Camlok connected cables. there is no benefit and chances are some inspector will think that it is a violation. Whether it is or not, depends on whether you think you have a utilization device or an installation. Me, I do not think anything connected up with extension cords is an installation.
 
zbang said:
In 40+ years I've never seen "type DLO" used for Camloks (or Tweco connectors)- we used to use welding cable then when types W and SC appeared everyone switched to those. Remember that "DLO" is a cable type which isn't in the NEC, do not use it as a general term for fine-strand flexible cord.

If you go to any of the large temp. power rental houses, you will get W, not "DLO".
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I used to do a fair amount of temp power work. Often exceeding 1 MW. 4/0 type W is by far most commonly used cable. Usually 50' with Camloks to be manageable. We also had some 2/0 sets for lighter jobs.
 
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dvcraven0522! said:
I do not see a table 404.5 in the NEC.
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Sorry, in article 400 Flexible Cords & Cables (not 404 Switches), about 8 pages earlier in the 2017 edition.

One more edit-
I think those unfamiliar with flexible cords/cable tend to think of all fine-strand cord/cable as DLO; to me this is kind of like calling all types of inflexible conduit/tubing (RMC, IMC, EMT, etc) "rigid" since they doesn't bend easily.
 
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dvcraven0522! said:
Good Morning - I am designing cables for temporary full generator back up with cam-locks. I have attached a spec. sheet for DLO cabling. I don't know much about this type of cable but we apparently have used this on previous designs.

In essence I plan on a 600 amp service with a manual transfer switch for the generator. Per the attached spec. I am not sure in the columns for amps what is meant by 1 & 2.

As an example for #4/0 indicates 260amps for (1) and (405 for (2). I would assume 2 cables. Is that correct?

Thank you for taking the time to review my question.
Click to expand...

Sometimes you need to find information hidden on datasheets when you read them.

1) The cable type is DLO...but it is also RHH/RHW. DLO is not a cable type in the NEC. RHH and RHW are found in the NEC, so you can use this cable for an installation covered by the NEC. But if you find some cheaper cable that is _only_ DLO, it might be a problem (as others have noted, the cable might not actually be required to be an NEC type for this particular installation).

2) The meaning of the ampacity values in columns 1 and 2 is defined in the footnotes. Column 1 is the ampacity based on NEC table 310.16, presumably interpolated for the conductor sizes that are not found in the NEC. Column 2 is the ampacity based on NEC table 310.17 again with the same interpolation. 310.16 is the table used for _most_ installation. 310.17 is for conductors strung in free air. You should know that for NEC installations you often cannot use the 90C temperature ratings, and it isn't clear if that interpolation for non-standard conductor sizes is allowed.

-Jon
 
winnie said:
Sometimes you need to find information hidden on datasheets when you read them.

1) The cable type is DLO...but it is also RHH/RHW. DLO is not a cable type in the NEC. RHH and RHW are found in the NEC, so you can use this cable for an installation covered by the NEC. But if you find some cheaper cable that is _only_ DLO, it might be a problem (as others have noted, the cable might not actually be required to be an NEC type for this particular installation).

2) The meaning of the ampacity values in columns 1 and 2 is defined in the footnotes. Column 1 is the ampacity based on NEC table 310.16, presumably interpolated for the conductor sizes that are not found in the NEC. Column 2 is the ampacity based on NEC table 310.17 again with the same interpolation. 310.16 is the table used for _most_ installation. 310.17 is for conductors strung in free air. You should know that for NEC installations you often cannot use the 90C temperature ratings, and it isn't clear if that interpolation for non-standard conductor sizes is allowed.

-Jon
Click to expand...

The application with camlock connectors needs article 400 portable cord, which would be type W or SC, not RHH/RHW. OP's application is extension cords not an installation. Articles 400 and 590 are what's going to apply.
 
augie47 said:
yummy tasting crow ??
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Me? Can someone show me what code section allows RHW to be used in this application?

590 says "Conductors shall be permitted within cable assemblies or within multiconductor cords or cables of a type identified in Table 400.4 for hard usage or extra-hard usage. For the purpose of this section, the following wiring methods shall be permitted (goes on to list NM, NMC, SE)"
 
Todd0x1 said:
Me? Can someone show me what code section allows RHW to be used in this application?

590 says "Conductors shall be permitted within cable assemblies or within multiconductor cords or cables of a type identified in Table 400.4 for hard usage or extra-hard usage. For the purpose of this section, the following wiring methods shall be permitted (goes on to list NM, NMC, SE)"
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Nothing permits the RHW to be run in the open...you would need a raceway or cable tray. Run in the open would require one of the cable types found in Table 400.4.
 
Todd0x1 said:
The application with camlock connectors needs article 400 portable cord, which would be type W or SC, not RHH/RHW. OP's application is extension cords not an installation. Articles 400 and 590 are what's going to apply.
Click to expand...

You are correct.

I saw RHH/RHW and read 'acceptable flexible cord'.

With that said, as a practical matter, I bet DLO/RHH/RHW meets all the standards but has not been evaluated and labeled as an article 400 portable cord.

With that RHW rating, this cable could be used as building wiring in conduit. But that would likely be a horrible idea. The conductors are fine stranded, the insulation is probably thick and 'sticky'. I would be perfectly comfortable using it with camlocks, but I've never been in a situation where an inspection would be triggered for such use.

-Jon
 
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