ERICO Practical Guide to Electrical Grounding - Manual (Page 48)

40 Practical Guide to Electrical Grounding
Fig. 2-38
On large flat roofs or gently sloping roofs, air
terminals are placed in the center area at intervals
not exceeding 50 feet.
Fig. 2-39
Air terminals must be placed within 2 feet of the
corners and edges of flat or gently sloping roofs
and the ends of roof ridges.
Fig. 2-40
Conductor may be welded to air terminal or
attached with an approved clamp.
Fig. 2-41
Dormers on buildings 25’ or less in height require
air terminals on the dormer projecting beyond the
2:1 pitch line require air terminals.
50 Feet Max
50 Feet Max
Over 50 Feet
Place Air Terminal
Anywhere Within
Hatched Area
24" Max
24" Max
2
1
1
2
Protected
Air Terminal
Required
Dormers
Grounding Book 4/14/99 10/5/99 6:01 PM Page 40 (Black plate)