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#84105 - 03/10/03 10:54 AM Bundled wiring?
Reel-Break Offline
Member

Registered: 04/04/02
Posts: 179
Loc: nc
Can someone please give some advise on this.Running wiring through holes in a web beam floor joist.I don`t have them packed but I have 4- 14/2 cables in some and 12/2 and 10/3 in others and ahj says I`m bundling must derate.I thought they had to be tied or taped. Thanks

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#84106 - 03/10/03 01:00 PM Re: Bundled wiring?
sparky Offline
Member

Registered: 10/18/00
Posts: 5545
'bundeling' is somewhat ill-defined, 310.15(b)(2)ex 5 can be used if your running MC or AC.

Table 310.15(b)(2)(a) w/310.16's ability to start @ the 90 deg collum should grant you some leverage

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#84107 - 03/10/03 02:03 PM Re: Bundled wiring?
Tom Offline
Member

Registered: 01/01/01
Posts: 1069
Loc: Shinnston, WV USA
If all you have is four 2 wire cables, there is no problem. You will be derating to 70% of the 90 degree column.

The trouble starts when you hit the fifth 2 wire cable in the bundle which requires a 50% derating.

As for the 3 wire cables, if this is a single phase system, the neutral is not considered a current carrying conductor and if this is a 3 way switch cable, only 2 wires are current carrying.
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#84108 - 03/10/03 03:46 PM Re: Bundled wiring?
George Offline
Member

Registered: 02/23/02
Posts: 380
Only if the joist holes are longer than 2' does the derating apply.

It is between you and your inspector as to what you will agree on.

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