An earth tester, also known as a ground resistance tester or ground tester, is an instrument used to measure the resistance of the earth connection in electrical systems.
This measurement is crucial for ensuring the safety and efficiency of electrical installations, as a proper earth connection helps to prevent electrical shocks and equipment damage by providing a safe path for fault currents to the ground. Earth testers are commonly used in various applications, including electrical installations, telecommunications, and power distribution systems.
They typically operate by injecting a small test current into the earth and measuring the resulting voltage drop, thereby calculating the resistance of the earth connection.
For electrical installations there are specific requirements.
Earth value is measured by “ohm”
For PLC it is required to maintain close to zero ohm . For panel, transformer, generator it is required to maintain below 5 ohm
There are many ways to reduce existing earth value.
Basically:- You can add salt, earthing compound, coir, coal dust to increase the earth value. By enhanced earth value it helps to create a low resistive path to grounded/ earthed excess current.
It has 3 probes :- For current, voltage and earth.
Suggested length between voltage and current rods are 25 feet for better readings. Earth probe is connected to the cu rod/ plate .