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Section 2 Installation
Figure 10-24. Above-roof clearance for overhead conductors. (OSHA)
8′ Min
18″ Min
4′ Max
12″
4″
3′
10′ 12′ 15′
8′
18′
Sidewalk
Driveway
Alley with
no trucks
Roadway with
truck traffic
Figure 10-25. Above-grade minimum clearances.
Service Clearances
Where overhead services are installed,
certain regulations concerning clearances must
be strictly observed. The NEC indicates that
clearances for overhead service drop conduc-
tors shall be as follows:
• Above roofs, Figure 10-24
A. 8′ as measured vertically from all points
B. 3′ if the slope is not less than 4″ in 12″
C. 18″ over an overhanging portion of a roof
• Above fi nal grade, Figure 10-25
A. 10′ above sidewalks
B. 12′ above residential driveways
C. 18′ above public alleys or thoroughfares
subject to truck traffi c
• At building openings, Figure 10-26
A. Not less than 10′ above a fi nished surface
platform, or other accessible surface
B. Not less than 3′ from a window in any
direction (except above the window)
Additional information regarding clearances is
found in Section 230.24 of the NEC.