Here is how you can measure whether the ground wire is well grounded
There are three ways to measure whether the ground wire is in good contact:
1. Multimeter measurement. Multimeters are also called multiplex meters, multimeters, three-purpose meters, multi-purpose meters, etc. They are indispensable measuring instruments in power electronics and other departments. They are generally used to measure voltage, current and resistance.
Instructions for use: When measuring, rotate the gear knob to select the correct gear (250V~). After that, insert the black test lead into the COM jack and the red test lead into the jack marked "V". Hold the watch in one hand, and hold the two test leads like chopsticks in the other hand - you can only hold the plastic rod, not the wires, let alone the metal on the front end. Touch the two test leads to the two lines to be measured respectively.
Judgment method: The voltage between the zero live wire and the voltage between the ground wire and the live wire is the same or slightly larger (not more than 5V), which proves that the ground wire is well grounded, and the smaller the gap between the two, the smaller the ground resistance. Otherwise, the grounding body is faulty.
2. To measure the light bulb, you need to deal with the light bulb in advance and connect two wires for later operation - if there is an idle light socket, you can directly install the light bulb on the light socket, and then connect the light bulb to the neutral line and the Between the live wire, ground wire and live wire (remember to turn off the power when wiring), observe the brightness of the bulb and analyze the results.
When the ground wire is well grounded, the brightness of the bulb is the same twice. If the ground body fails, the bulb will not light. If the ground resistance is just slightly greater, the bulb will only dim slightly.
3. Ground resistance tester. Generally speaking, this equipment will be used for testing during project acceptance. The ground resistance tester can accurately measure the ground resistance of the ground wire. Generally, the ground wire used in our homes is considered qualified as long as the ground resistance is not greater than 4 ohms.
