How to measure if the earth wire is well grounded
Measuring whether the ground is in good contact with the following three methods:
1, multimeter measurement, multimeter is also known as the multiplex meter, multi-meter, triple meter, traditional meter, etc., is an indispensable measuring instrument for power electronics and other departments, generally to measure voltage, current and resistance as the main purpose.
Usage: When measuring, rotate the gear knob to select to the correct gear (250V~). After that, insert the black meter pen into the COM jack and the red meter pen into the jack marked with "V". Hold the meter with one hand and the two pens with the other hand like chopsticks - only plastic rods should be held, not the wires and not the front metal. Touch the two pens to the two wires to be tested.
Judgement method: the voltage between the zero fire line and the ground and the voltage on the fire line is the same or slightly larger (not more than 5V), proving that the ground is well grounded, and the smaller the difference between the two, proving that the grounding resistance is smaller. Conversely, the grounding body failure.
2, light bulb measurement, beforehand to deal with the bulb, connect two wires to, in order to operate after - if there is an unused lamp port can be directly installed in the lamp port on the bulb can be, after the bulb were connected to the zero line and the fire wire, ground and between the fire wire (remember to disconnect the power when connecting the line), to observe the brightness of the bulb, and analyse the results.
In the case of a well grounded earth wire, the bulb has the same brightness twice. If the ground is faulty, the bulb does not light up. If the grounding resistance is only slightly larger, then the bulb is only slightly darker.
3, grounding resistance tester, generally speaking, in the project acceptance, will use this equipment for testing. Ground resistance tester, can accurately measure the size of the grounding resistance of the earth wire. Generally our family with the ground, as long as the grounding resistance is not greater than 4 ohms even if qualified.
