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#23690 - 03/24/03 09:03 PM What do the "N" and "T" mean?
ThinkGood Offline
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Registered: 08/07/02
Posts: 1081
Loc: Milwaukee, WI
Regarding clamps for non-metallic cable, what do the "N" and "T" mean?

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#23691 - 03/24/03 09:40 PM Re: What do the "N" and "T" mean?
sparky66wv Offline
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Registered: 11/17/00
Posts: 2232
Loc: West Virginia
The N stands for Non-metallic Cable

The T stands for "tubing" and is a reference to Loom tubing.

These clamps are listed for both NM cable and Loom.

Hence the name "Loom Clamps"...
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#23692 - 03/25/03 04:31 AM Re: What do the "N" and "T" mean?
wocolt Offline
Member
Registered: 12/06/02
Posts: 110
T stands for tube or loam(???), are those holes big enough to get two K and T wires in one hole with the tube.
As you know you cannot separate the wires ie one per hole because of inductive heating.
just my 2 cents.

WOC
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#23693 - 03/25/03 04:39 AM Re: What do the "N" and "T" mean?
Redsy Offline
Member
Registered: 03/28/01
Posts: 2056
Loc: Bucks County PA
K&T wiring normally is separated throughout the system and it enters boxes via 2 separate holes. I'm not sure that there is enough separation of the wires in small wall cases to cause inductive heating problems, which is also of course related to the amount of current flowing.
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#23694 - 03/25/03 08:16 AM Re: What do the "N" and "T" mean?
SvenNYC Offline
Member
Registered: 08/19/02
Posts: 1691
Loc: New York City
Quote:
As you know you cannot separate the wires ie one per hole because of inductive heating.


Could you elaborate on this? I don't understand. How can separating wires cause heating?

I thought you had to derate when you bunched up wires because that is when they can potentially start heating up.
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#23695 - 03/25/03 08:32 AM Re: What do the "N" and "T" mean?
Bill Addiss Offline
Member
Registered: 10/07/00
Posts: 3875
Loc: NY, USA
Sven,

That's a good Tech Area question.
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#23696 - 03/25/03 06:21 PM Re: What do the "N" and "T" mean?
harold endean Offline
Member
Registered: 02/16/02
Posts: 2233
Loc: Boonton, NJ
You are suppose to cut the notch out between the two holes in order to reduce the magnetic build up between the 2-K&T wires. This way each K&T wire enter the box through it's own space.
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#23697 - 03/25/03 08:46 PM Re: What do the "N" and "T" mean?
ThinkGood Offline
Member
Registered: 08/07/02
Posts: 1081
Loc: Milwaukee, WI
Thanks for the replies.

...The things one can learn on this board!!!!
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#23698 - 03/25/03 09:22 PM Re: What do the "N" and "T" mean?
Bill Addiss Offline
Member
Registered: 10/07/00
Posts: 3875
Loc: NY, USA
Sven,

Look at 300.20
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