On 11/3/17 7:15 AM, john@kk9a.com wrote:
How is ground resistance measured?
With an AC ohmmeter specifically designed for this application. Mostly,
it's a matter of standard probes, standard measuring voltages and
currents, etc. so that everyone's measurements are the same.
googling "grounding system resistance testing" turns up lots of links:
http://www.esgroundingsolutions.com/how-to-do-electrical-grounding-system-testing/
http://www.weschler.com/_upload/sitepdfs/techref/gettingdowntoearth.pdf
http://www.aemc.com/techinfo/techworkbooks/ground_resistance_testers/950-WKBK-GROUND-WEB.pdf
there's a difference between measuring soil resistivity and grounding
system resistance, but the same kinds of measurement tools are used.
I'm sure you could use standard ham DMM and a variac + isolation
transformer to do something that is functionally similar.
The tricky parts are the standardized electrodes (that's just a matter
of getting the right length and diameter) and not having your
measurement perturbed by ground currents from other sources and
interference. Kind of like the problems with measuring an 160m antenna
when there's strong AM stations nearby.
John KK9A
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Mot R36 related to NUMBER of installed ground
rods
From: jimlux <jimlux@earthlink.net>
Date: Fri, 3 Nov 2017 05:52:59 -0700
"The contractor shall install sufficient ground rods in accordance with
document XYZ that the measured ground resistance is less than 5 ohms."
At the end of the job, the customer goes out, measures the resistance,
finds it's 4.2 ohms and says "you get paid"
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|