** Or the mixed color of yellow and green is the ground wire, blue and gray, which are easy to distinguish. Compare the two colors, the darker one should be the live wire. The neutral line is blue, green or black.
Wires refer to the conductors that transmit electrical energy. Divided into bare wire, electromagnetic wire and insulated wire. Bare wires do not have an insulation layer, including copper flat wires, aluminum flat wires, overhead stranded wires and various profiles (such as profiled wires, bus bars, copper bars, d aluminum, etc.). It is mainly used for outdoor and indoor busbars and switch boxes. Magnetic wire is an insulated wire that generates a magnetic field when energized or induces a current in a magnetic field.
It is mainly used for windings of motors and transformers and other electromagnetic equipmentassociates. Its conductor is mainly copper wire, which should have a thin layer of insulation and good electrical and mechanical properties, as well as heat resistance, moisture resistance, solvent resistance and other properties. Different properties can be achieved by choosing different insulating materials.
Detailed information:
Selection criteria
1. Select copper core wires: For wires and wires, you must first have good conductivity. There are copper core wires and other wires on the market. Copper core wire is the most practical type for interior decoration. However, copper core wires are divided into several types, including large radius copper core and multi-strand copper core.
2. Yarns with high load capacity: ConsumptionThe electricity in the house fluctuates when it is at its maximum, we turn on the television, the air conditioner, the computer, the lights and the drinking water. , hairdryer, etc. If the carrying capacity of the wire is not strong, coupled with the hot summer, it is easy for the wire to burn due to the high temperature, causing a fire.
3. Good sealing performance. The appearance of some wires is easily deformed and cracked. If water leaks somewhere, electrical appliances may burn out, short circuit or even cause fires and casualties. Therefore, the wire must have a hard outer coating and good sealing performance.
4. The main wire should be thick core. The so-called main wire refers to the two main wires between the main power supply and all electrical devices. The main wire should use thick copper core wire, because the main wire carries the ch loadaque electrical appliance and requires thick copper wire with excellent performance. Multi-core cables can be selected for bypass.
References:
Baidu Encyclopedia - Wires
Home electricity is alternating current, so what is the difference between neutral wire and live wire?
Live wires are the power wires that carry electricity in a circuit. The neutral line is the line drawn from the neutral point (N) on the secondary side of the transformer. It forms a loop with the phase line (L) to power the electrical equipment.
1. Distinguish by color: in the power cable, green and red represent phase A, phase B and phase C respectively (the three-phase live wire represents the neutral wire, and yellow and green represent theground wire).
2. Use an electric pen to distinguish: the neon tube will glow when you test the live wire with an electric pen, but not the neutral wire.
3. Use a voltmeter to distinguish: the voltage between different phase wires (that is, live wire) is the line voltage 380V, and the voltage between phase wires (live wire) and the neutral wire (or a good grounding body) is The phase voltage is 220 V and the voltage between the neutral line and a good ground is 0 V.
The live wire and the neutral wire touch each other
Since the voltage between the two is equal to 220 volts and the resistance between the two contact points is almost zero, the current at this level The time is very long. Tremendous heat will be generated at the point of contact with the neutral wire, causing an electric spark. The temperature at the spark will be high enough to meltthe metal wire. If the human body contacts the live wire and the neutral wire at the same time, regardless of whether it touches the ground at the same time, it will receive an electric shock (called double-wire electric shock).
Reference for the above content: Baidu Encyclopedia-FireWire
Let's start with the alternator. An alternator is mainly made up of magnets and coils. We learned in college that when the coil cuts the magnetic induction wire, it can generate an induced emf, which means there is voltage and there is current when connected to a circuit.
However, there is a problem with the continuously rotating coil, that is, the coil requires an external circuit, which makes rotating the coil inconvenient. We know that motion is relative, so we can make the coil stationary and let the magnet move. The magnet will continue to rotate under the action of aexternal force to generate electricity. The image below is the simplest model. For the alternating current generated by this type of coil, there is no difference between the live and neutral wires. These two wires have exactly the same properties. If we touch a wire with our hands, we will receive an electric shock.
However, this method of generating energy does not fully utilize the power of the magnet, because only when the magnet rotates towards certain areas in the vertical direction does a certain current is formed, while from other angles the power of the magnet has not been used well, so the generator must be changed at that time, that is, it must be rolled up several times. This is the three phase generator we are currently using, which. uses three sets of coils to produce electricity, and each set of coils has a phase difference of 120. The model looks like the picture below.
GThanks to this connection, all three coils can generate electricity simultaneously, and since the phase difference of these coils is 120°, the voltage generated by each coil is also 120° out of phase. You will find that if you use three sets of coils, you need to connect six wires, which greatly increases the use of long-distance transmission cables and the cost will be very high. So, what can be done to change this situation? This changes the connections of a coil. We always keep the same position of the coil, make one end of the coil the common contact and connect it to ground. We call this public line the neutral line. The earth of the plant is connected to the earth where we live. Just output three lines directly. The neutral line on the user side is actually a grounded wire (this is the main reason why the neutral line does not cause an electric shock).
InIn other words, one generator can produce three power systems, each system is Different users provide electricity, and through the deployment of the power grid, the power consumption of these three sets of circuits is basically maintained in a balanced state. Therefore, based on this criterion, we can calculate the total current of our three sets of circuits.
If the power in all three sets of lines is the same, we can equate the three sets of circuits to three identical resistors, then the relationship between current and voltage in each line is the same (according to Ohm's law). If we calculate it this way (requiring trigonometric calculations), we will get that the current in the ground wire is zero, so the current actually flows in the three live wires (of the four wires connected to the generator, one is neutral). wire to ground, and three are FireWire). And the neutral wire, which is the ground wire, has virtually no current. So this is the difference between the live wire and the neutral wire. In fact, the neutral wire is the ground wire. When the power of the three power lines is basically the same, there is no current at the common end of the neutral wire.
Home alternating current is therefore actually three-phase alternating current, and the current essentially flows between three live wires, not the single-phase alternating current that we simply imagine. In this case, there is no difference between the neutral and live wires.