This is how you can check that the earth 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.
Extended information:
Basic functions of multimeter:
1. Measurement: resistance, AC and DC voltage, AC and DC current, on and off.
2. Expansion: capacitor, inductor, diode and transistor.
Multimeter has the advantages of multiple uses, wide measuring range, and ease of use. It is the most commonly used tool in electronic measurement. It can be used to measure resistance, AC and DC voltages and DC voltages. Some multimeters can also measure the main parameters of transistors and the capacitance of capacitors. Mastering the use of a multimeter is a basic skill in electronic technology.
3. Common multimeters include pointer multimeters and digital multimeters. The pointer multimeter is a multi-functional measuring instrument with a meter as the core component. The measured value is read by the pointer of the meter. The measured values of digital multimeters are directly displayed in digital form on the LCD screen, which is easy to read, and some also have voice prompt functions.
4. The DC current range of the multimeter is a multi-range DC voltmeter. The voltage range can be expanded by connecting a closed-circuit voltage dividing resistor in parallel with the meter. The DC voltage range of the multimeter is a multi-range DC voltmeter. The voltage range can be expanded by connecting a voltage dividing resistor in series with the meter. Different voltage dividing resistors have different corresponding ranges.
