Just noticed something in everyone's favorite Table 130.7(C)(15)(a) that I hadn't noticed before...

Under Metal clad switchgear, 1 kV through 38 kV (Page 70E-36 of the 2012 edition), we have two items:




Now, coming from the perspective of a service company that does a lot of relay/controls troubleshooting at facilities where arc flash studies have NOT been performed, what were the intentions of NFPA, and what are the ramifications of these two items?

Example:
Traditional GE PowerVac gear with relays and meters mounted on the door, 125Vdc control power, and 3-phase 120Vac ±5% PT circuit. When you open the door you expose the dead front of the breaker, but the only exposed energized conductors are the control power and the PT bus.
Do they really intend for me to suit up to HRC 4 to pull the 5A 120Vac PT circuit fuses?

Before I had seen the lines referenced above, my reasoning would have been:
1) There are no MV conductors exposed, nor being interacted with, therefore arc flash protection is based on the control and PT circuits alone.
2) There is no arc flash protection specified for DC circuits.
3) Under Panelboards or other equipment rated 240V and below (page 33) it lists



4) So whether I'm dealing with insulated fuse blocks, or open fuse blocks where I have to use an insulated fuse puller, my HRC requirement is no higher than 1.

What is your take on the above?

Thanks,
Nathaniel

2012 Edition of 70E page 38, Table 130.7(C)(15)(b) DC Tables >100V <240V.
Work on energized electrical conductors... HRC 1
The HRC goes up with short circuit current but I can't imagine much SC current for your situation.

If an arc flash study had been performed, you would most likely be faced with a label that is based on a MV arc incident energy. You won't find a label specifically for the control compartment.

Do you use the MV PPE requirement from the label? Do you use the the 70E task tables for LV AC and DC? I think that the problem is not only the lack of an arc flash study, but the lack of a hazard/risk analysis and a well thought out electrical safety procedure that covers your situation.