Ground Rod Resistance Test

In areas where driving ground rods may be impractical the two point method can be used.

Ground rod resistance test. Built to withstand an entire spectrum of ground testing methods fluke s family of earth ground testers have been designed to be accurate safe and easy to use. The lower it is the better job it does. Step 1 connect your length of wire to a metal stake in the ground. Step 5 measure the ground or leakage current if you wish to find out about the ground or leakage current all that you have to do is to set the rotary switch to ma or a.

The nfpa and ieee recommend a ground resistance value of 5 ohms or less while the nec has stated to make sure that system impedance to ground is less than 5 ohms specified in nec 50 56. Unfortunately as time goes by factors such as ground rod corrosion soil moisture high salt content high temperatures and loss of contact of your wires as well as others may increase the resistance of ground rod s hence affecting its effectiveness. If your ground rods are placed at least one rod length apart you can use a formula to estimate the earth resistance of multiple grounding rods. In some instances ground rods can be installed in areas where the earth has a lot of resistance.

So if you are using 10 foot ground rods you must place. Ground ring ground rods. Run the wire to your test location. Multiple ground rods yield a lower resistance to ground than a single rod.

For a safe electrical system your ground rod resistance should have a very low resistance value. You can only do this by using the fall of potential method with a three terminal earth ground resistance tester. Simultaneously perform a bonding test of the grounding conductor necessary to complete the return path. An ideal ground rod resistance should be below 3 ohms.

However we can estimate the resistance to ground using scenario b. For example the national electric code requires no greater than 25 ohms of resistance in a ground system. Check your clamp on tester s manual if it uses another kind of configuration. With this method the resistance of two electrodes in a series is measured by connecting the p1 and c1 terminals to the ground electrode under test.

Check errant current flow to ground for operator safety and give an overview of ground system dynamics. Unfortunately there is not one standard ground resistance threshold recognized by all certifying agencies. P2 and c2 connect to a separate all metallic grounding point like a water pipe or building steel. If this is the case for your ground rod the best solution is to drive a different rod into a different location.

To properly test the resistance of a ges you must follow some simple rules. Browse our top selling 1623 2 geo earth ground resistance meter 1625 2 geo earth ground tester and the 1630 ground resistance meter today. Test the resistance of a single rod in a series or array. Make sure that you have stripped back the insulation from both ends of the wire to allow for a good connection.