lighting protection

[montanaklr1]

My question is regarding lightning protection for an antenna system. Should the air terminal be taller than the antenna mast? Will it cause interference if it is taller than the mast?

 

[jumper]

NFPA 780 4.6.2.1 seems to say the air terminal tip should be 10" higher. I know little about this stuff, so do not take my answer as anything definitive.

 

[sgunsel]

Depends on the antenna geometry, relationship to the mast, frequency, at minimum.

 

[bphgravity]

It is likely an additional air terminal is not needed for a metal antenna mast as the mast and its support structure serves as the strike termination device. If the antenna mast is within the zone of protection of other air terminals, then no additional consideration is needed. If in doubt, the structure should be bonded to the rest of the LPS using main-sized conductors and listed fittings.

See section 4.17 of the NFPA 780...