How to use the multimeter to check the grounding wire is normal?
It is easy to detect by the clamp type meter, without the ground wire being disengaged, but the actual test is impedance. If the earth wire has current, the error of detection will be greater.
The bridge method has high accuracy, but it needs to be separated from the ground wire. It is necessary to insert a ground pile every 20 meters and 40 meters. It takes more than ten minutes to test a point.
The multimeter is not able to detect whether the earth wire is normal. Grounding resistance detection is usually done by bridge method, grounding resistance tester and clamp type meter grounding resistance tester. They all need special test equipment.
