ECN Forum Forums Code Related Discussion NEC & other Code issues Bundling in Panels

I come across panels all the time that have wires cable tied together forming bundles in the wiring troughs. It makes for a neat looking job. As I understand it, over 24" of bundling requires derating,
I cut the cable ties when I see this, and the wires remain right where they were usually. In reality, I have accomplished nothing.

What's your take on this??

I don't recall ever seeing heat damaged insulation under these conditions, either in a wireway or panel enclosure. Of course, one man's experiance is a very limited database.

I could see where this might be a problem with conductors that are loaded on a continuous basis. I feel there are two factors that prevent damage most of the time, the first being are loads that are not continuous in nature. the second is that many conductors are already oversized based the actual load and requirements of limiting small conductors per 240.4(D) to a value lower than their actual ampacity.

Tom

IMO if the conductors are bundled longer than 24" it is a violation.

I have never seen any damage from bundling but was that the question?

I have seen heat damage once in a bundle, but the case was extreme.

3' of bundle in 42 circuit panel (All of the circuits), 2' bundled in 2" EMT, another 2'+ bundled in a gutter, essentially 5-6' of the same conductors tightly bundled. They were pretty warm, and all the whites had yellowed, and insulation crispy long before thier time. They must of thought it looked real nice when they closed it up.

So yeah, I too don't like bundling in the panel, and consider it part of the 24" if it is done. I always bundle grounds and neutrals (24"), but leave the hots free. And will often cut the hots loose when I see it done by someone else.


[This message has been edited by e57 (edited 12-12-2004).]

In any given panel, bundling is happening simply do to the close proximity of the conductors with or without wire ties isn't it?

Mark, in some cases, where these neutrals are not neutrals but just grounded conductors of two wire circuits, bundling could be an issue.

Roger

Yeah Roger, Fully aware that neutrals can be current carrying, and only bundle 24" in the panel only for them. Thanks for pointing that out though. Believe it or not, I think panel manufactures have figured that out too, as it is often hard to bundle neautrals more than 24" with the bars on both sides in most panels these days. (Although you could if you tried)
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As far as close proximity.... It's a grey area I would guess, because all of the conductors are in close proximity, if you look at that way. What kind of spacing should be maintaind, and how would you maintain it? (Im imaging some sort of device that would look like a comb to hold all the conductors from eachother...) But a far cry from being zip tied every few inches forming tight bundles where the conductors are held tight against eachother.

[This message has been edited by e57 (edited 12-12-2004).]

I hate it when wires are wire tied together. When the cover is on a panel or trough, who is it impressing?? Makes it a pain in the butt to trace out a circuit. I'm in alot of places where I'm not familar with the installation. I sometimes have to trace out a lot of control wiring and having them bundled so I can't pull one to see where it moves sucks.

What about bundling 10-40' of NM cables.
I see residential homeruns bundled all the time and don't understand why the installation passes.

Hey Redsy you gotta start buying more donuts for the inspector.I see lots of things go under the bridge. Like you it never goes under my bridge but I try to comply always unless I miss something by accident.The donut keeps their writing hand ocupied.Please don`t bash me guys I`m kidding.

Hey Redsy- Bagels and creme cheese works too. Keeps both hands busy and I can't think and eat at the same time.