Grounding Test Wells: Essential for Electrical Safety | ES Grounding
The purpose of a ground test well is two-fold: to be able to quickly and easily measure resistance-to-ground of the grounding electrode and/or to measure point-to-point continuity (resistance) from one electrode to another. The first part, resistance-to-ground, is a measurement of the total resistance to the flow of electricity that the earth is providing against the ground system under test.
Grounding Electrode Test Wells
The purpose of a ground test well is two-fold: to be able to quickly and easily measure resistance-to-ground of the grounding electrode and/or to measure point-to-point continuity (resistance) from one electrode to another.
The first part, resistance-to-ground, is a measurement of the total resistance to the flow of electricity that the earth is providing against the ground system under test. As the 3-point fall-of-potential method is not usable for any active grounding system, only the clamp-on or induced frequency method can be used for testing the resistance-to-ground of electrodes with a test well. This involves a hand-held meter with large jaws that are “clamped” around a grounding conductor under test, thus the need for a test well.
The second part, which is simple point-to-point continuity (resistance) measurements, can be done even at an improperly installed test well. Point-to-point testing from a ground test well back to a reference point can be very valuable for understanding the integrity and conductivity of a grounding system. The goal is to install ground test wells that are capable of allowing both measurements.