Nec 645

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Rob_009

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...I'm referencing NEC 2005 for this question...

NEC 645.5(B) allows cord and plug connections (power cables) under raised floors when the stipulations of 645.4 are met.

Paragraph 645.5(D)(5) indicates cables other than the ones complying with (D)(5)(a), (D)(5)(b), or (D)(5)(c) shall be listed as DP.

Back to cord and plug connections (power "cables"): has anyone ever seen a DP rated power cable? I've seen DP rated communication cables. Am I missing something in (D)(5)(a), (D)(5)(b), or (D)(5)(c)?
 
Compliments of UL:

Data processing cable is identified by marking on the jacket or on a marker tape under the jacket. This marking includes one of the following Type designations:

DP-1 ? Indicates cable rated 600 V in conductor sizes 18 AWG to 1000 kcmil copper or 12 AWG to 1000 kcmil aluminum or copper-clad aluminum. This cable does not spread flame to the top of the tray in the Vertical-Tray Flame Test in UL 1581, "Reference Standard for Electrical Wires, Cables, and Flexible Cords."

DP-1P ? Indicates cable rated 600 V in conductor sizes 18 AWG to 1000 kcmil copper or 12 AWG to 1000 kcmil aluminum or copper-clad aluminum. This cable meets the requirements of NFPA 262, "Standard Method of Test for Flame Travel and Smoke of Wires and Cables for Use in Air-Handling Spaces."

DP-2 ? Indicates cable rated 300 V in conductor sizes 24 to 8 AWG copper or 12 to 8 AWG aluminum or copper-clad aluminum. This cable does not spread flame to the top of the tray in the Vertical-Tray Flame Test in UL 1581 .

DP-2P ? Indicates cable rated 300 V in conductor sizes 24 to 8 AWG copper or 12 to 8 AWG aluminum or copper-clad aluminum. This cable meets the requirements of NFPA 262 .

DP-3 ? Indicates cable with no voltage rating in conductor sizes 30 to 10 AWG copper for general use and copper-clad steel for use in coaxial conductors. This cable does not spread flame to the top of the tray in the Vertical-Tray Flame Test in UL 1581 .

DP-3P ? Indicates cable with no voltage rating in conductor sizes 30 to 10 AWG copper for general use and copper-clad steel for use in coaxial conductors. This cable meets the requirements of NFPA 262 .

Type DP-3 and Type DP-3P cable is for use in circuits having maximum available ac voltage of 30 V, dc voltage of 60 V, peak voltage of 42.2 V, VA of 100 and current of 8 A or in circuits designated DP-3 in UL 60950, "Information Technology Equipment."

Cable with aluminum conductors is surface printed "AL."

Cable with copper-clad aluminum conductors is surface printed "AL (CU-CLAD)" or "Cu-Clad."

Type DP-1, DP-2 and DP-3 cable that complies with the Limited Smoke Test requirements specified in UL 1685, "Vertical-Tray Fire-Propagation and Smoke-Release Test for Electrical and Optical-Fiber Cables," is surfaced marked with the suffix "-LS."

The temperature rating of the cable is 60?C unless otherwise marked on the cable.

Cable containing optical fiber members is identified with the suffix "OF."

Type DP-1, DP-2 and DP-3 cable which has a damage height that does not exceed 4 ft. 11 in. when tested in accordance with the FT-4 Vertical-Tray Flame Test in UL 1581 may have the additional marking "FT-4" on the surface.

For conductor termination information, see Electrical Equipment for Use in Ordinary Locations (AALZ ).

REQUIREMENTS

The basic standard used to investigate products in this category is UL 1690, "Data Processing Cable."

UL MARK

The Listing Mark of Underwriters Laboratories Inc. on the product is the only method provided by UL to identify products manufactured under its Listing and Follow-Up Service. The Listing Mark for these products includes the UL symbol (as illustrated in the Introduction of this Directory) together with the word "LISTED," a control number, and the product name "Data Processing Cable, Type DP."
 
If you check on the UL website under manufacturers for the DP type listed cable, there are many. Unfortunately, I don't know of any that make a standard product (power supply or power strip cord) with DP cable. Supposedly they will do it special order since they have a UL listing for DP cabling product, but claims of very long lead time are what make folks just put the receptacle flush with the raised floor or above the raised floor.
2008 has a wording change that may help when your jurisdiction adopts 2008 NEC.
 
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