Placement Of Coax Lightening Arrester

[WSGI699]

It appears that when assembling my rooftop antenna system I can attach my coax lightening arrester either to the SO-239 of the antenna that will be clamped near the top of my 7-foot aluminum tubing mast or, I could splice it into the LMR-400 coax with an SO-239 and a PL-259 end near the bottom of the mast just before the coax enters the wall of the house.  The base of the aluminum tubing mast will also have a ground wire attachment and both ground wires will be fixed to an 8-foot ground rod some 25-feet away, 4-feet out from the house.  My question is ‘in which of these 2 locations should I install the coax lightening arrester’ regardless of what rigid antenna is at the top of the mast’ ?

[SteveShannon]

6 minutes ago, WSGI699 said:

It appears that when assembling my rooftop antenna system I can attach my coax lightening arrester either to the SO-239 of the antenna that will be clamped near the top of my 7-foot aluminum tubing mast or, I could splice it into the LMR-400 coax with an SO-239 and a PL-259 end near the bottom of the mast just before the coax enters the wall of the house.  The base of the aluminum tubing mast will also have a ground wire attachment and both ground wires will be fixed to an 8-foot ground rod some 25-feet away, 4-feet out from the house.  My question is ‘in which of these 2 locations should I install the coax lightening arrester’ regardless of what rigid antenna is at the top of the mast’ ?

It wouldn’t hurt to connect it at both places, but the NEC says to use at least one right where the coax enters the house.

The bible on this is a document from Motorola named R56, and it has been linked many times, but for a person wanting to understand the basics I really like this document:

https://reeve.com/Documents/Articles Papers/Reeve_AntennaSystemGroundingRequirements.pdf

[Socalgmrs]

What does the local code say? What does your insurance say? What does the maker of the equipment say?   I’d stick with that instead of opinions of these guys.  If something happens and insurance won’t pay or the city/county finds you at fault for burning down your neighbors house or causing a wild fire you’re gonna wish you asked the right people.  

[WSGI699]

13 minutes ago, SteveShannon said:

It wouldn’t hurt to connect it at both places, but the NEC says to use at least one right where the coax enters the house.

The bible on this is a document from Motorola named R56, and it has been linked many times, but for a person wanting to understand the basics I really like this document:

https://reeve.com/Documents/Articles Papers/Reeve_AntennaSystemGroundingRequirements.pdf

 

[WSGI699]

Thanks Steve.  Scanning the R56 I can see I need the education.  Thanks again.

[WSGI699]

18 minutes ago, Socalgmrs said:

What does the local code say? What does your insurance say? What does the maker of the equipment say?   I’d stick with that instead of opinions of these guys.  If something happens and insurance won’t pay or the city/county finds you at fault for burning down your neighbors house or causing a wild fire you’re gonna wish you asked the right people.  

Thanks to you too Socalgmrs.  Think I’ll study the Professional Engineer’s R56 reference and then take your advice. Good call!

[SteveShannon]

Here’s a link to the R56 document:

https://www.blm.gov/sites/blm.gov/files/Lands_ROW_Motorola_R56_2005_manual.pdf

[WRYZ926]

And the R56 document is not an opinion either. It is directly from a manufacturer. 

One should always follow the NEC (National Electric Code) when installing antennas, antenna masts and towers.

The Reeves document makes things easier to understand and worth reading.