NFPA 70E Section 130.5(F) allows two options for selecting the proper level of PPE:
(1) The incident energy analysis method in accordance with 130.5(G)
(2) The arc flash PPE category method in accordance with 130.7(C)(15)
Either, but not both, methods may be used on the same piece of equipment. The results of an incident energy analysis to specify an arc flash PPE category in Table 130.7(C)(15)(c) is not permitted.
As mentioned above, 130.7(C)(15) can be used instead of performing an incident energy analysis. When choosing this option, Table 130.7(C)(15)(a) or (b) is used to determine the arc-flash PPE category and the arc-flash boundary. (See image)
In order to even begin to use this table, the qualified person must already know several key pieces of information:
If any one of the above are unknown, then Table 130.7(C)(15)(a) or (b) cannot be used, and an incident energy analysis must be performed instead of using the Table.
NFPA 70E Table 130.7(C)(15)(a) Arc-Flash Hazard PPE Categories for Alternating Current (ac) Systems |
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Equipment |
Arc Flash PPE Category |
Arc-Flash Boundary |
Panelboards or other equipment rated 240 V and below Parameters: Maximum of 25 kA available fault current; maximum of 0.03 sec (2 cycles) fault clearing time; working distance 455 mm (18 in.) |
1 |
485 mm (19 inches) |
Panelboards or other equipment rated >240 V and up to 600 V Parameters: Maximum of 25 kA available fault current; maximum of 0.03 sec (2 cycles) fault clearing time; working distance 455 mm (18 in.) |
2 |
900 mm (3 feet) |
600-V class motor control centers (MCCs) Parameters: Maximum of 65 kA available fault current; maximum of 0.03 sec (2 cycles) fault clearing time; working distance 455 mm (18 in.) |
2 |
1.5 m (5 feet) |
Which of the following is true when working on a 120/208V panelboard while energized? The panelboard has 25 kA of available fault current, an overcurrent device with a max clearing time of 2 cycles and 18 inches is needed for a safe working distance.
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