Junior high school physics three way plug The knowledge points of junior high school physics three w

It just so happens that our physics teacher has talked about it in class, so I will tell you the general meaning (because the teacher spoke quickly and did not remember it completely, so it is only for understanding).

First of all, you should know the causes of electric shock: the human body is directly or indirectly connected to the fire wire and the two ways of electric shock of the person Single-wire electric shock (the person touches the fire wire and steps on the ground) Double-wire electric shock (the person touches the neutral line and the live wire, and the foot does not step on the ground).

Then, the purpose of the ground wire leads to this, when a person touches the metal shell, the current flows from the live wire to the metal shell, and flows to the ground on the way. At this time, it is equivalent to the resistance on the circuit being short-circuited, and the person is also short-circuited, and there is no current passing through, so the person will not be electrocuted.

If you don't understand what I said in the previous section, please look at the following diagram (I drew it by referring to the picture in my notebook where the physics teacher wrote on the blackboard).

As for what you said about the three-way plug being a parallel circuit, I can only regret to tell you that it is definitely not.

The meaning of the grounding wire is to turn the current to the ground, so that the human body is short-circuited, and the safety and ...... of electricity is ensured(Why did our teacher talk about it again.......)）

As for the actual circuit diagram you mentioned, I can't see the diagram, I don't know what type it is, and I can't answer ......

However, our teacher has said a sentence, you can guarantee to win the general drawing in the third year of junior high school (not the competition questions are OK), called "left zero right fire on the ground", the left side of the three-way plug is connected to the zero line, the right side is connected to the fire wire, and the upper side is connected to the ground wire.

The human body is resistive, and when the current is outdated, it will cause the voltage to electrocut. When the current leaks, the machine shell is electrified, and the grounding wire will direct the current to the ground, because the ground is 0 potential, and the human body is short-circuited at this time, so the current will not flow through the human body.

That's right、、、 the human body has a certain resistance, the wire and the human body are connected in parallel, and no current passes through the human body. So the human body will not be electrocuted... By the way, haven't you explained it all?。。

Forehead ......I suggest you buy an encyclopedia, Khan, you can ask all these questions. Sweat, waterfall sweat!!

Left zero and right fire grounding, this is a three-wire plug slippery. It means that the left side is connected to the neutral wire, the right side is connected to the live wire, and the upper side is connected to the ground wire. There are two and three plugs, and general electronic equipment equipment uses three-wire plugs.

The reason is that there is a voltage of 220 volts between the live wire and the neutral wire, and the two-pin plug only has the neutral wire. The ground wire of the three-wire plug is connected to the metal shell of the electrical appliance, and the current of the neutral line of the live wire is channeled into the ground, which will not cause harm to the human body. If there is no ground wire, the voltage of 220 volts between the neutral line of the live wire, and the voltage of not less than 36 volts is unsafe voltage for the human body.

This ensures safety.

Three wires, there is a live wire and a zero wire, and there is a grounding wire, generally the live wire and the neutral wire, connected to the bottom of the three plugs, the two left and right are not separated, the grounding wire must be connected to the top of the three plugs independently, as long as it is clear which one is grounded, it is good to connect, the general grounding is a flower wire, two colors together of the line.

Socket wiring method:

The three colors of the power cord are brown, blue, and yellow-green flower wire.

The wiring diagram is as follows:

The upper hole of the three-way socket is the ground wire, the left zero (n) and the right fire (l). In general, single-phase electrical equipment, especially mobile electrical equipment, should use three-core plugs and matching three-pin sockets. The three-pin socket has a special protection zero (ground) jack, and when using the zero connection protection, some people often only connect the terminal head of this hole directly with the neutral wire introduced into the socket only in the bottom of the socket, which is extremely dangerous.

In the unlikely event that the neutral wire of the power supply is disconnected, or if the fire (phase) wire or neutral wire of the power supply is reversed, the metal parts such as the housing will also carry the same voltage as the power supply, which will lead to electric shock. Therefore, the dedicated grounding jack should be connected to the dedicated protective ground wire when wiring.

The red line is connected to the BAI live line, the DU green line is connected to the working zero line, and the yellow line is connected to the ground protection wire. You can turn the plug backwards.

DAO came to see the specialty, and there was a "L" end of the wire, yes"n"One end is connected to the working ground wire (that is, the neutral line), and the other end is to connect to the protective ground wire.

The basic common sense of life, how to connect the three-pin plug to the wire, is actually very simple.

The yellow-green is connected to the middle, the brown is the line of fire on the right, and the green is on the left.

Yellow-green color grounding wire, green and brown phase wire and neutral wire respectively.

The flower line (yellow and green interphase line) is connected to the middle. The other two colors are connected to both sides.

The longer of the three feet is grounded, which can be called the grounding pin, and the other two shorter feet are used to connect household appliances to the circuit, which can be called conductive feet. When designing the power plug, the grounding pin was consciously designed to be a few millimeters longer than the conductive pin in consideration for the user's safety. This is because when the three-pin plug is inserted, the grounding pin first touches the grounding wire in the socket, so that the grounding protection can be formed first, and then the power supply is turned on; Conversely, when pulling out the three-pin plug, the conductive pin is separated from the conductive end in the power outlet first, and then disconnected after the grounding pin.

If the metal shell of household appliances is charged due to damage to the insulator and other reasons, then the grounding foot will form a grounding short-circuit current, so that the metal shell of household appliances is grounded and discharged to the ground, so that people are not electrocuted, and play a role in safety protection.

To protect the safety of electrical use, the long grounding can prevent electric shock.

Black, white, and green are ground, zero, and fire wire, respectively.

Directly test it with a meter or pen and confirm.

At present, the national code only stipulates the protective grounding wire, requiring the use of yellow and green two-color wires. As for the black, white, and green wires of the three-phase plug, you can directly test it with a multimeter or electric pen.

Yes, the two-pin socket also has an upper and lower zero.

From a safety point of view, it is necessary to fire left and right.

Including, the three phases are the live wire, the neutral wire and the ground wire.

The 220 volt electricity has a ground wire, and the 380 volt three-way plug has no ground wire.

L: Line of Fire (The letter of the logo is"l"live wire) n: zero wire (the flag word rent mother is"n"Naught Wire) E: Earth Wire

When installing the three-wire road, we must strictly abide by the provisions of "fire wire into the switch, zero line into the lamp head", "left zero right fire, and connect the fiber on the side", in order not to have a safety accident.

There is no regulation for the order of the second neutral live wire, because the direction of the plug can be reversed.

Hope it helps.