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Joined: Aug 2002
Posts: 1,081
T
Member
Regarding clamps for non-metallic cable, what do the "N" and "T" mean?

[Linked Image from 65.108.216.53]

Joined: Nov 2000
Posts: 2,236
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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"...


-Virgil
Residential/Commercial Inspector
5 Star Inspections
Member IAEI
Joined: Dec 2002
Posts: 110
W
Member
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

Joined: Mar 2001
Posts: 2,056
R
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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.

Joined: Aug 2002
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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. [Linked Image]

Joined: Oct 2000
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Sven,

That's a good Tech Area question.


Bill
Joined: Feb 2002
Posts: 2,233
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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.

Joined: Aug 2002
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T
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Thanks for the replies.

...The things one can learn on this board!!!!

Joined: Oct 2000
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Sven,

Look at 300.20


Bill

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