[SBE] conversation topic: how often do you check tower ground wires?

[Cowboy]

On Wednesday 13 February 2008 12:51 pm, A9xw at cs.com wrote:

>  Those buried radials won't last forever. Copper, turning green, then dust.


 TRUE, but they will last nearly forever in some areas.


>  So  

>  what is the thinking on how often to dig one up and check the condition, or 

>  measure the ground resistance?


 When you think of it, or when local experience dictates it's a good idea
 ( such as the marshes along the coasts ) or once every couple years.
 For me, every time I visit a site. Being an independent full time project
 field engineer, and not a station maintenance engineer, my perspective
 is slightly different, and so is my motivation. ( since I do ground systems
 in addition to everything else, as a routine part of vacant field to final
 sign-off turn-key )


>  How about those that are not AM towers (ground  

>  effectiveness can be gauged by field strength on radials), but your typical 

>  1000', 2000' 


 These are typically grounded for lightning only, and use heavy cable which
 will last a l-o-n-g time.
 Still every couple years isn't a bad idea.
 Field readings to determine the effectiveness of an existing radial field are
 only effective near-field, and if you have the original walk-in data for reference.
 Far field readings may suggest, but should never be taken as definitive.


>  tower lightning protection ground system?  Didn't use copper because someone 

>  steals it?  Ground rods vs radials?


 Radials are always RF, *never* lightning !

 Many ( most ? ) of you I realize are not familiar with repetitive pulse
 power handling at gigawatt levels, but that's exactly what lightning is !
 Megavolts and kiloamps. Literally, the Power of God !
 ( if you don't respect it as such, then He can explain it in person ! )
 About all we can do, is "suggest" a preferred path, and do it as correctly
 and in as straight a line as possible.
 While radials can dissipate *some* of the energy in the precursor, ( much
 like the theory behind the stati-cat products ) they are effectively absent
 during a strike of any magnitude.
 Very much like ground rods do almost nothing at all for RF at any 
 usable frequency, RF and lightning grounds are confused at your own peril.

-- 
Cowboy

http://cowboys.homeip.net

Does someone from PEORIA have a SHORTER ATTENTION span than me?