The so-called zero line electrification refers to the potential difference between the zero line and the earth. The zero line of the diesel generator is electrified, which means that it is not well grounded. If it is well grounded, the current will flow into the ground, and it will not be detected by the electric pen. If the neutral wire is detected to be charged with an electric pen, either the neutral wire is broken or the contact is not good. In fact, the neutral line is electrified, which is obviously a kind of fault. Since the diesel generator room usually adopts the precautionary measures of flat iron grounding, even if the neutral line is powered, it will not cause electric shock. But this is not the correct way to deal with the electrification of the neutral line. We must find out the cause of the electrification of the neutral line, and then carry out corresponding technical treatment.
What is Electrified Wire?
Two-phase AC diesel generator connection output cables are divided into season wire, live wire and ground wire, among which the logo letter of the neutral wire is “N”, the logo letter of the live wire is “L”, and the logo letter of the ground wire is “E”; The logo letter of the zero wire grounding is “PE, and the logo letter of the neutral wire and the ground wire is “PEN”. The voltage difference between the live wire and the neutral wire maintains a sinusoidal oscillating voltage difference. Since the earth and the neutral wire have the same potential, the live wire and the ground wire also maintain a sinusoidal oscillating voltage difference. When you think that the neutral line is not charged because the neutral line is grounded, and the ground touches the neutral line because there is no potential difference, no current will form. So there is a feeling that the neutral line is not charged.
Both the neutral wire and the live wire come out of the power supply, and the positive direction of the current is to go out from one end, pass through the external equipment, and enter from the other end to form a loop. The difference between the neutral wire and the live wire is that one of the two terminals of the power supply is pressed to the ground. The zero line is connected to the neutral point of the diesel generator and the grounding electrode of the generator, that is to say, the resistance value from the quarter line to the neutral point and the grounding electrode of the diesel generator is very small, and the resistance value from your body to the ground is lower than that of the zero line The resistance value to ground is much larger.
When the human body comes into contact with fire, the person is standing on the ground, and the current of the live wire flows into the earth or the season wire through the human body, and an electric accident will occur, but the contact wire will not be shocked. Connect the shell of the externally conductive electrical appliance with the state line. In the case of leakage, the current will flow directly into the ground through the ground wire without passing through the body, thereby avoiding electric shock accidents.
The reason for the electrification of the neutral line
The fuselage of the diesel generator is a conductive material, if there is leakage, it will cause the current to flow to the neutral line of the diesel generator. This situation generally occurs after the diesel generator is aged or damaged, resulting in damage or deterioration of the insulating material.
Winding open circuit or short circuit
The windings of diesel generators may be open or short circuited due to long-term use or vibration. This causes current to flow to the quarter wire of the diesel generator, electrifying it.
The zero line is wrongly connected
When some manufacturers design diesel generators, they mix the zero line with other lines, so that some wires that should have been connected to other lines are reversed with the neutral line, so that the current will pass through the neutral line of the diesel generator.
The zero line of the diesel generator needs to be grounded. If the grounding is not good, it will cause the quarter line to be charged. This situation is usually caused by excessive grounding voltage or disconnection of the grounding line.
A malfunctioning capacitor in a generator can cause current to leak from the capacitor, energizing the neutral wire. The reason for the failure of the capacitor may be aging, overload, etc.
The solution to the charged neutral line
Replace the insulating material
Check the insulation of the diesel generator to make sure that the insulation is not damaged. If the fuselage leaks electricity, the insulation material needs to be replaced to reduce the flow of current to the neutral line of the diesel generator.
When there is a winding open circuit or short circuit, the winding needs to be repaired to prevent the current from flowing to the neutral line of the diesel generator.
Replace the neutral wire
If you find a problem with the quarter line connection, you need to separate the zero line from the line that should be connected. If there is a problem with the quarter line, it can be replaced with a new zero line to avoid electrification of the zero line of the diesel generator.
Sound detection grounding
- Check the grounding of the diesel generator to ensure that the grounding voltage is not too large, and if the grounding voltage is too large, measures such as increasing the number of grounding wires or replacing the grounding electrode can be taken.
- Once the neutral line is disconnected, the electrical equipment that is connected to the zero will lose its protective effect. Once the equipment leaks electricity, it will cause personal electric shock. It will also cause personal electric shock accidents. Therefore, the distribution line should be repeatedly grounded, and the grounding voltage of repeated grounding should not exceed 100. Its effect diagram is shown in Figure 2 and Figure 3.
Replace the capacitor
Capacitors play a very important role in brushless generators. It can improve the stability of the generator, protect the surrounding electronic equipment, and at the same time improve the efficiency of the generator. Therefore, whether it is normal or not occupies a very important position. If the capacitor is found to be faulty, it should be replaced in time.
It is a common problem that the neutral line of the diesel generator is charged, but as long as we take the correct treatment method, this problem can be effectively solved. In the process of using diesel generators, we should always pay attention to the operation of the equipment, find problems in time and take measures to understand the reasons and solutions for the zero line of diesel generators, which is very important for people who use diesel generators. By strengthening safety awareness, and using and maintaining diesel generators correctly, it is possible to effectively prevent the zero line of diesel generators from being charged and ensure the normal operation of equipment and personal safety.