Table 4-2. Hazard/Risk Category Classifications for Work Tasks on Grade - Cont'd

Electrical Safety, O&M - index
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51

UFC 3-560-01

6 December 2006

Including change 1, 7 December 2006

Task (Assumes Equipment Is Energized,

Hazard/Risk

and Work Is Done Within the Flash Protection Boundary See Note 7)

Category

Outdoor disconnect switch operation (gang-operated, from grade)

Note 1. Maximum of 25 kA short circuit current available, 0.03 second (2 cycle) fault clearing time.

Note 2. Maximum of 65 kA short circuit current available, 0.03 second (2 cycle) fault clearing time.

Note 3. For < 10 kA short circuit current available, the hazard/risk category required may be reduced

by one number.

Note 4. Maximum of 42 kA short circuit current available, 0.33 second (20 cycle) fault clearing time.

Note 5. Maximum of 35 kA short circuit current available, up to 0.5 second (30 cycle) fault

clearing time.

Note 6. For < 25 kA short circuit current available, the hazard/risk category required may be reduced

by one number.

Note 7. Refer to Table 130.7(C)9(a) in NFPA 70E for additional information.

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