For example the national electric code requires no greater than 25 ohms of resistance in a ground system.
Ground rod resistance to earth.
The lower it is the better job it does.
Ground ring ground rods.
You can only do this by using the fall of potential method with a three terminal earth ground resistance tester.
Make sure that you have stripped back the insulation from both ends of the wire to allow for a good connection.
Chemical treatment of soil is a good way to improve earth electrode resistance when you cannot drive deeper ground rods because of hard underlying rock for example.
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.
The rule is that the lower the resistance it has the better job it does.
Four of the most common methods of ground resistance testing used by test technicians are discussed below.
For a safe electrical system your ground rod resistance should have a very low resistance value.
If you do not have one already you can easily install a ground rod for your home.
Step 1 connect your length of wire to a metal stake in the ground.
The procedures for earth resistance testing are referenced in ieee standard no.
Go back to ways to improve earth electrode resistance 3.
The goal in ground resistance is to achieve the lowest ground resistance value possible that makes sense economically and physically when contacting the earth also known as the soil ground rod interface.
It is beyond the scope of this manual to recommend the best treatment chemicals for all situations.
In areas where driving ground rods may be impractical the two point method can be used.
In some instances ground rods can be installed in areas where the earth has a lot of resistance.
If this is the case for your ground rod the best solution is to drive a different rod into a different location.
For instance if a ground rod is driven into a very rocky and dry area it may not conduct electricity into the ground well.
2 point dead earth method.
Run the wire to your test location.
The function of any ground rod is to dissipate the current that is recovered in any faulty electrical circuit near your house to the earth surrounding the ground rod.
