Table K-1-Working Clearances
Nominal voltage to ground | Minimum clear distance for conditions1 | ||
(a) | (b) | (c) | |
Feet2 | Feet2 | Feet2 | |
0-150 | 3 | 3 | 3 |
151-600 | 3 | 31/2 | 4 |
1 Conditions (a), (b), and (c) are as follows: (a) Exposed live parts on one side and no live or grounded parts on the other side of the working space, or exposed live parts on both sides effectively guarded by insulating material. Insulated wire or insulated busbars operating at not over 300 volts are not considered live parts. (b) Exposed live parts on one side and grounded parts on the other side. (c) Exposed live parts on both sides of the workspace [not guarded as provided in Condition (a)] with the operator between.
2 Note: For International System of Units (SI): one foot = 0.3048m.
Table K-2-Minimum Depth of Clear Working Space in Front of Electric Equipment
Nominal voltage to ground | Conditions1 | ||
(a) | (b) | (c) | |
Feet2 | Feet2 | Feet2 | |
601 to 2,500 | 3 | 4 | 5 |
2,501 to 9,000 | 4 | 5 | 6 |
9,001 to 25,000 | 5 | 6 | 9 |
25,001 to 75 kV | 6 | 8 | 10 |
Above 75kV | 8 | 10 | 12 |
1Conditions (a), (b), and (c) are as follows: (a) Exposed live parts on one side and no live or grounded parts on the other side of the working space, or exposed live parts on both sides effectively guarded by insulating materials. Insulated wire or insulated busbars operating at not over 300 volts are not considered live parts. (b) Exposed live parts on one side and grounded parts on the other side. Walls constructed of concrete, brick, or tile are considered to be grounded surfaces. (c) Exposed live parts on both sides of the workspace [not guarded as provided in Condition (a)] with the operator between.
2 NOTE: For SI units: one foot = 0.3048 m.
Table K-3-Elevation of Unguarded Energized Parts Above Working Space
Nominal voltage between phases | Minimum elevation |
601-7,500 | 8 feet 6 inches.1 |
7,501-35,000 | 9 feet. |
Over 35kV | 9 feet + 0.37 inches per kV above 35kV. |
1 NOTE: For SI units: one inch = 25.4 mm; one foot = 0.3048 m.
29 C.F.R. §1926.403