Has anyone labeled arc resistant / arc rated switchgear? If so, what do you put on your label? For example, say the calculation indicates 40cal PPE if you do not consider the arc rated benefit. If the heavy doors are open or the panels are removed then it’s not arc resistant any longer. Do you need two labels? One indicating no PPE when close and 40cal when open?

No comments from the group? Ok, if this were your study how would you handle labeling this equipment?

Good question. It seems logical to either have 2 labels or use one label with some statement about doors open / doors closed. Judging from the results of the "question of the week" a while back, not too many people seem to be using arc rated equipment yet. However, it is slowly gaining traction.

NFPA 70E HRC tables rate this category 0 for doors closed and category 2 or 4 with door open, depending on the task.

I would think you could do something similar. Category 0 with doors closed and calculated Ei with doors open. The problem that I see is makeing sure this is part of you safe work practices so people don't confuse the situation.

The conservative approach would be to label the Ei as the default with a note about category 0 if doors are closed.

Sounds like a good idea. If you use one label with Ei and a note about category 0 for doors closed, I wonder if any software manufacturers can accomodate this with their label formats?

This is what we do for our two lineups of 38 kV arc resistant switchgear. We list an HRC category of 0 for the door closed, then the result of the calculations for door open. The big problem with arc resistant Switchgear is that the racking mechanisms occasionally jam and require work with the door open. We use remote racking on everything installed in the last ten years or so, so the HRC 4 requirement for racking doesn't apply to us in many cases.