Free Air or not

[John W Anderson]

My question is; Is wire in a distrubution panel considered to be in free air?
Is there an article in the NEC that I can refer too.

 

[iwire]

My question is; Is wire in a distrubution panel considered to be in free air?
Is there an article in the NEC that I can refer too.

In my opinion no.

But even if it was what would that gain you?

 

[btharmy]

in a distrubution panel

You answered your own question. If it is '"in a distribution panel" then it can not at the same time be in free air. Free air implies the cable can dissipate heat better because it is not enclosed in anything that will contain the heat generated. I suppose if the cabinet is ventilated with fan forced air, and can be proven to not retain the heat genrated by current carrying conductors, you might have an argument. But if it is in a distribution cabinet, one can only imagine the heat generated by all the other conductors and overcurrent devices in the same cabinet would override the effect of ventilation.