Does a lightning protection system attract lightning?
No, a lightning protection system will not attract lightning to the structure it simply intercepts the charge and give it what it wants, a low resistance (safe) path to ground.
My home has an electrical ground isn’t this for lightning as well?
No, basically a structures electrical ground protects against harmful currents produced within the electrical system by providing it with its own path to ground. (If your toaster shorts out you don’t get electrocuted). A lightning protection system protects the structure from a direct strike by intercepting it and diverting it to ground.
Aren’t lightning protection systems unsightly?
The modern lightning protection system can be installed with minimal or no aesthetic effect to a home. The large tripods seen on older barns and structures are not required by current standards. On new construction the only visible portion of the system would be the air terminals or “lightning rods” with all of the conductor installed internally. On an existing structure it is also possible in many cases to install most of the conductor internally. In any case aesthetics and durability are always top considerations when a system is installed.
Does lightning strike the same place twice?
Absolutely lightning can and often does strike the same location more than once.
What are the voltages involved in a lightning strike?
Lightning can exceed 50 million volts
What maintenance is involved with a lightning protection system?
A properly installed system will require no routine maintenance and should provide you with years of service. The main issue’s that come up with system maintenance involve other work being performed on a structure which may disrupt the system such as roof repair, siding or trenching near the foundation which could disrupt system components. Also future additions to a structure may not be protected by the existing system. Older systems should be inspected for integrity and compliance to current standards. HVLP does provide for free inspections on residential systems.
What type of materials can be used for lightning protection systems and what are the differences?
Lightning protection systems can be installed primarily using copper (including brass and bronze components) and aluminum.
Sometimes the structures building materials dictate what must be used. Since we cannot install copper on aluminum or galvanized steel roofing materials aluminum would need to be used just as copper would need to be used on a copper roof. For most installations, primarily residential the choice comes down to budget and aesthetics.
An aluminum system is less expensive then copper however it is less durable and its components are larger than the components of a copper system. For example a copper class 1 air terminal is 3/8” in diameter its aluminum counterpart is 1/2” in diameter.