ERICO Practical Guide to Electrical Grounding - Manual (Page 42)

34 Practical Guide to Electrical Grounding
10. Section 3-19.4: Where the building structural steel
is used as the main conductor of the lightning
protection system, a ground rod or other ground
terminal shall be connected to approximately every
other perimeter steel column. Such connection shall
be made at the base of the column and at intervals
not to exceed an average of about 60 feet.
10" Min
10" Min
10" Min
>1/2 H
>1/2 H
H = Over 24"
H = Over 24"
Air Terminals Height And Supports
Fig. 2-16 Fig. 2-18
No Air Terminal; Roof Edge
Covered Under Higher
Air Terminal Protection.
150 Foot
Radius
20' MAX
25' MAX
24" Or
Higher
Less
Than 24"
Fig. 2-17
Air terminals less than 24” in height are located at
20 feet maximum intervals. If 24 inches or higher,
they can be spaced at 25 feet intervals.
Air terminals located in areas where personnel
may be present, 60 inch terminals are
recommended at mid-roof locations.
Grounding Book 4/14/99 10/5/99 6:01 PM Page 34 (Black plate)