When are Arc Flash labels not required

[Mr. T]

Basic question about when, if ever, it can be assumed an arc flash is so unlikely that labeling is not required. The specific example I have in mind is a cubicle on the back side of a breaker panel (480V) that contains only cables and terminals, and no moving parts. The cover is bolted, not hinged. Typically, the only reason to open this cubicle would be to replace/repair the conductors, in which case everything would be de-energized. Since the unit must still be considered hot until verified with a sniffer, in theory, the possibility of an arc flash would still exist while the cover was off if the Lock-out procedure was done incorrectly.

Is a label required or can this scenario be considered sufficiently unlikely as to not require a label.

 

[romex jockey]

Well the only thing i've found is this Mr T>>>

110.24 Exception: The field marking requirements in 110.24(A) and
110.24(B) shall not be required in industrial installations where condi‐
tions of maintenance and supervision ensure that only qualified
persons service the equipment.

My only problem is, i'm not qualified to say who might be qualified.... ~RJ~

 

[charlie b]

Well the only thing i've found is this Mr T>>>

That article is about marking service equipment with the available fault current. Not the same as arc flash labels, which are discussed in 110.16. As I read that article, the equipment the OP is describing does not fall into any of the categories that would require an arc flash label.

 

[mayanees]

70E 130.(4)(H) Equipment Labeling

70E 130.(4)(H) Equipment Labeling

It's only equipment that is likely to require examination (while energized) per the above-referenced section so there's no need to label.