Question on Ground Resistance Testing Methods

[michaellabeit]

I've got a customer who needs their grounding electrodes tested for an inspection (8 electrodes total, in a 4x4 configuration). We do grounding resistance tests but typically for electrodes outside or for setting up mobile power plants, where there's plenty of room for lengthy fall-of-potential tests. The building where the electrodes are located is cramped (see picture). I'm assuming that they are all connected via a grounding grid underneath, but I will verify that once I head out there obviously. Any thoughts on the best method of testing these?

[Kalbi_Rob]

I've got a customer who needs their grounding electrodes tested for an inspection (8 electrodes total, in a 4x4 configuration). We do grounding resistance tests but typically for electrodes outside or for setting up mobile power plants, where there's plenty of room for lengthy fall-of-potential tests. The building where the electrodes are located is cramped (see picture). I'm assuming that they are all connected via a grounding grid underneath, but I will verify that once I head out there obviously. Any thoughts on the best method of testing these?

I would perform one of two test.
First option: You can probably perform a fall-of-potential test thru the roll-up door on each ground rod.

Second option: Perform fall-of-potential test on outside of building steel, then perform 2-point test to each ground rod.

Or lastly you can perform a combination of the above, with a fall-of-potential to one ground rod, then 2-point to the other 2.