Bundling in a panel...

[Diddle720]

So I live in Denver Colorado and I recently got called for bundling in a panel because I had my wires in the corners of the panel and then zip tied them to keep it all looking nice. This is the way I was taught to make up panels and is the way I've done it for years. But because my zip ties where tight the inspector called me on bundling. He did give me a code article but don't remember what it was it's been a couple months since this happened and i have a few panels to do on this job and just want to make sure on what bundling is considered in a panel. I was told that I can zip ties the wires but the ties need to be lose to allow air flow. Can you help give me a code article for this situation?

 

[arazu]

310.15(B)(2-3)?

 

[infinity]

The bundling would need to be more than 24" to require derating, if exceeding 24" then this is typically permitted by 310.15(A)(2)Exception.

310.15(A)(2) Selection of Ampacity. Where more than one ampacity
applies for a given circuit length, the lowest value shall be
used.
Exception: Where two different ampacities apply to adja-
cent portions of a circuit, the higher ampacity shall be
permitted to be used beyond the point of transition, a dis-
tance equal to 3.0 m (10 ft) or 10 percent of the circuit
length figured at the higher ampacity, whichever is less.

 

[arazu]

The bundling would need to be more than 24" to require derating, if exceeding 24" then this is typically permitted by 310.15(A)(2)Exception.

I agree. I have been called on that though. I didn't argue the 24". I just cut the zip ties and everyone was happy.

Knowing the guy who called me on it his argument probably would have been that even though the zip tie is only touching the wires at one point it's causing the entire length of wires to be forced together and thus the rule applies.

Edit: Went to fix a typo and deleted half my post. It's back now. =)

 

[Dennis Alwon]

The zip ties only bundle the wire in that spot not 24" . If he is complaining about the wire being too close then I think there could be an argument either way. Just spread the wires a tad between the ties.