What Is a Ground Test?

A ground test is usually performed on electrical wires to ensure that they are able to resist current overload. Grounding makes sure that electricity doesn't build up and cause damage to wiring, outlets and devices that use current. It diffuses excess electricity away from the device or system into the ground. Circuit and clamp-on resistance testers can be used to conduct a ground test.

The purpose of any ground test is to make sure that high amounts of electrical current are able to flow through the wiring properly. Most electrical wiring in buildings and grids are grounded to prevent damage in the event that a large amount of current gets into the system. Lighting strikes are a common example. Grounding wires allow that current to rapidly flow away from the system into the soil.

Some individuals may wish to conduct a ground test on the electrical outlets in their homes or offices. A circuit tester can be plugged into the outlet to test the ground wire. The test makes sure that there is active power to the outlet, that the grounding wire is in the correct position and that the outlet's grounding feature is working properly. If the circuit tester does not light up correctly, it could indicate that the outlet is not grounded.

Outlets or components in an electrical system that a ground test indicates are not grounded should not be used and immediately corrected. Continuing to run current through components that are not grounded could result in personal injury or serious damage to the wiring or device. Conductors and electrodes in an electrical system can also be tested for proper grounding. When the current resistance is low in a conductor, it indicates that it is properly grounded.

A licensed or trained electrician should perform a ground test due to numerous safety and technical issues. He might use a voltmeter on a conductor to make sure the ground connection is not receiving too much current. A high amount of voltage may indicate that there is an overheating problem or that the connection is faulty. The testing process for a ground electrode is a bit more complicated.

When testing is conducted on an electrode, an electrical system's breakers and main control panels usually need to be temporarily shut off. The electrode needs to also be disconnected from the system. A fuse can be connected to one of the breakers and the electrode. After the fuse is connected, the breaker can be turned on and as long as the fuse blows, the grounding connection is good.