Measuring ground rod reistance.
Measuring ground rod reistance.
Our earth ground measuring meter has relatively short leads. max 75 ft for the current probe. I have made some current probes with a distance of 500 ft for the current probe, voltage probe, 330 ft and ground rod probe is 166 ft. I have measured the resistance of the cabling and since I am measuring a series es voltage drop, I should be able to deduct the actual cabling 14 gauge wiring resistance from the outcome. The building that I am taking measurements has a concrete slabe, 75 by 100 and with a r-bar grid. Trying to get a way from the ground rod and equipotential has me making up extra long cables. Someone on the forum said, that if a mesh, metal or re-bar is welded together and form one plate in regards to mother earth, that the NEC does not require the 25 ohm measurement. If that is so, where do I find it. I have 2011 code. That would be a blessing. I am somewhat skepitical of running conductors out to 500 ft or more. The meter says it has a potential of 50 VAC. Seems kinda weak. (6) 1.5 vdc batteries
Thanks for brain storming this one with me. I am appreciative in advance. It is a federal government job.
r/
Ben