Grounding Test

Think of grounding as the foundation of a house that holds all of your electrical systems. Without it, the whole thing comes tumbling down.


Grounding tests fall into two categories: those you do to ensure your installation meets grounding specifications, and those you do to make sure it still meets grounding specifications. Why the first category? Your electrical system needs a low impedance path to ground for protecting people and equipment. Why the second? Because grounding systems deteriorate and so does their performance. Such deterioration is unavoidable, as it is the result of the ion exchanges that make grounding systems effective in the first place.


What is ground testing? Ground testing is the verification that resistance between your grounding system and earth meets the specifications of the Electrical Standard. The standard answer to the requirements is to drive a second rod and call the job done. However, doing so may not protect your installation for purposes beyond those of the Electrical Standard.


To test ground levels on your system, measure the resistance between a ground connection and earth. This is not as straightforward as it seems. Results are approximations; even though you are dealing with precise measurements. The variables that affect the measurement can, and usually do, change your readings.