The only way I've known of testing ground rods without a ground-testing meter, is to disconnect the EGC, place a 5A cartridge fuse in line with the EGC and a 120V line, turn on the power *briefly*, and if the fuse blows, you're done, if it don't, then drive another rod. Gives you a "threshold" of 24 Ohms, rather than the NEC 25, but it works. If you've got (closer to) 125V (we do here in Greenbrier County) then it's a perfect 25 Ohms.
Plus, you can gather nightcrawlers after the test!
I also read this in (I think) an older version of the American Electrician's Handbook (say, 1970's?)...
Kids, don't try this at home!
-Virgil Residential/Commercial Inspector 5 Star Inspections Member IAEI
Re: resistance on groung rod#81983 10/10/0211:07 AM10/10/0211:07 AM
Reel-Break: Most contractors in our area just drive 2 rods from the get-go. Most AHJ's require documentation of the 25 ohms or less, and a meter to test and print results is pricey. Rods are cheap, and driving them with a roto hammer is quick.
66 thats a test to remember, I'll pass it on to my guys. Do you need "documentation" for your AHJ's or???
Re: resistance on groung rod#81986 10/10/0207:54 PM10/10/0207:54 PM
66 the reason we can't use our flukes to do this is because we don't know exactly where to stick the other probe into the earth. this is why biddle can get a grand for these instructions supplied with their meters. watt
Re: resistance on groung rod#81988 10/11/0206:16 PM10/11/0206:16 PM