Matter
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Lightning Protection
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Each year, lightning strikes cause many deaths and inju­
� ries, and billions of dollars in property damage in the
United States. Lightning can have a voltage charge as high as
thirty million volts (30,000,000V), and a current discharge of
over fifty thousand amperes (50,000A).
1 . 7 Lightning Protection
To protect property against direct lightning strikes, a lightning protection
system must be installed to direct its current flow around nonconduc­
tive structures or buildings down into the Earth. Strike termination
devices (air terminals or lightning rods) are placed on top of the struc­
ture to be protected. They are connected to each other by large wires
and attached to ground rods or other electrodes in the Earth. For
proper protection, the lightning protection system should be installed in
accordance with the requirements contained in NFPA 780, Installation
of Lightning Protection Systems. ► Figure 1 -20
erm1na 10n ev1c
cted together by
conductors attach
und rods d riven int
rth d i re �t l \ g htning
Caution : Lightning protection is intended to protect the
building itself, nof the associated electrical equipment.
Copylight 2019. www.MikeHolt.com
► Figure 1 -21
Article 242 provides the general installation and
connection requirements for overvoltage
protection and overvoltage protective devices.
► Figure 1 -22
► Figure 1 -20
�---------<[ Caution }>---------�
/;\. The lightning protection system is intended to protect
� the building or structure, not the associated electrical
equipment inside. To reduce damage to electrical equipment
from a nearby lightning event, surge protection devices (SPDs)
must be installed on the electrical system in accordance with
manufacturer's instructions and the National Electrical
Code. ► Figure 1 -21 and ► Figure 1 -22
Mike Holt Enterprises • www.MikeHolt.com • 888.NEC.C0DE (632.2633)
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