Matter I Lightning Protection A 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) I 15
