Two three phase asynchronous motors of the same power, whether the star connection current is large

P= 3 Ulicos P: Active Power ul: Line Voltage IL: Line Current Cos: Power Factor.

Y connection: ul = 3up il = ip

Connection: ul=up il=3ip

China's 3kw motor connection, some imported motors are often marked 380V when Y connection, 220V time connection.

When you connect the connected motor to the Y connection, it is equivalent to the Y start is not converted, if the load is running, the current far exceeds the rated current, and it is easy to burn out.

When you connect the motor connected by Y, the winding runs over voltage and the insulation is easily damaged. Moreover, the iron loss increases, and the motor is seriously heated, and it is also easy to burn.

Two three-phase asynchronous motors of the same power, one is a star connection at the factory and the other is a triangle connection from the factory, then his current is the same large.

If it is a star connection, change to a triangle connection, then the current will increase, and finally the motor will burn out.

If it is a triangle connection, change to a star connection, then the current will be smaller, the power of the motor will be smaller, if the load is not large, then the motor will work normally. If the load is large, the current will still be very large, and the motor will burn out.

The same power does not say anything. It is even more impossible to compare the current size of the star connection and the triangle connection.

The "power" of the motor is actually a very "virtual" concept. It has a lot to do with the speed, for example, a 3kw 4-pole 50hz motor, if the frequency is changed to 100hz, then its power will be 6kw. The 3kw 4-pole motor and the pole, and the 6kw 2-pole motor are basically the same (volume) size.

I think that the current size of the three-phase asynchronous motor has nothing to do with the number of poles of the motor, because the number of poles will only affect the speed of the motor, and the larger the number of poles, the smaller the speed. As you said, when two three-phase asynchronous motors of the same power are connected to the same voltage circuit, the current of the stator winding when the triangle connection is greater than that when the star connection is used, the relationship between them is three times that of the following sign.

Two three-phase asynchronous motors of the same power, and the same voltage and the same number of stages, the current of the star delta connection is the same.

When connected in a triangle, the phase voltage is equal to the line voltage; When connected in a star shape, the phase voltage is equal to 1 3-line voltage. That is, under the same line voltage, when the same motor adopts the triangle connection method, its power is 3 times that of the star connection.

1. The star connection method and the triangle connection method both refer to the winding connection method of the motor itself, and the star connection method refers to the three-phase end of the motor winding together, and the three-phase head end is the power supply end.

2. Because the three-phase live wire (A, B, C) of three-phase alternating current is 220V, the phase difference between them is 120 degrees, and the voltage difference between the three phases is 380V, so it cannot be replaced by three live wires of the same phase.

3. It is basically a time, that is, 3 times the three-phase asynchronous motor can be powered by a single-phase power supply after the phase-shifting capacitor is connected, but the three-phase asynchronous motor is divided into star connection and triangle connection according to the connection mode of the stator winding, and the phase voltage on the phase winding of the motor corresponds to different relationships with the line voltage in each phase winding of the motor.

4. 220 380V (Y) is written on the nameplate of the motor, which means that when the power supply is 220V (three-phase), the motor should be connected in a triangle, and when the power supply voltage is 380V, the motor should be connected in a star shape.

5. When the triangle is connected, the load is directly connected between the two live wires, and the line voltage is beared, and when the star is connected, the load is connected in series between the two live wires, and it bears half of the line voltage (phase voltage), because the load is connected in series between the two live wires is a vector relationship, so the phase voltage is not half of the two live wires, but 1 times 220V.

When the power supply is three-phase 380V, the power below 3KW adopts the star connection method.

If the nameplate stipulates that the motor connected to the star is mistakenly connected into an angular shape, the winding withstand voltage is increased by 3 times, the winding current is increased by 3 times, and the line current supplied to the motor is increased by 3 times. The heating of the motor will exceed the allowable value, and the winding will heat up for a long time, and the insulation will accelerate the aging and damage the motor.

Star triangle starts.

It is a step-down start, which is achieved at the expense of power in exchange for reducing the starting current.

Star start: X-Y-Z is connected, A, B, C are terminated with three-phase AC voltage of 380V, and the winding voltage of each phase is 220, which is greatly reduced compared with the direct addition of 380V starting current, which avoids the impact of excessive starting current on the power grid. The torque is relatively small at this point, but the motor can reach a certain speed.

Because the starting current of the motor is proportional to the power supply voltage, the starting current provided by the power grid at this time is only 1 3 of the full voltage starting current, but the starting torque of Yan Feng Xiangpei is only 1 3 of the full voltage starting torque

Angular operation: After the star-shaped starting motor lasts for a period of time (about tens of seconds) to reach a certain speed, the electrical switch puts six terminals.

When converted into a triangle connection and connected to the 380V power supply again, the winding voltage of each phase is absolutely 380V, the torque and speed are greatly improved, and the motor enters the operation process under rated conditions.

1. Triangular connection:

If it is a line connected to the user, the voltage of each coil is U line = U phase = 220V.

In the circuit where the load (coil) is connected in a triangle, because the load (coil) of each phase is connected between two phase wires, the phase voltage of the load is the line voltage of the power supply (power grid), that is, U line = U phase.

2. Star connection:

If it is a line connected to the user, the voltage of each coil U line = 3 times the root number U phase = 380V.

The star connection method is a wiring method between the three-phase AC power supply and the three-phase electrical appliances. The ends of the three windings of the three-phase power supply, X, Y, and Z, are connected together to become a common point O, and three end wires are drawn from the beginning A, B, and C.

It is a system in which three sinusoidal power supplies with the same frequency, equal amplitude and 120° phase difference are connected to the external power supply in a certain way, and the voltage of the coil is, U line = 3 times the U phase voltage of the root number.

Summary. What is the difference between the star connection and the delta connection of the three asynchronous motors of kilowatts, speed and current? They are not the same at all, the triangle connection should be three times as powerful as the star connection.

The motor is a star-shaped connection, and if you want to change it to a star-shaped connection, it becomes a kilowatt.

What is the difference between the star connection and the delta connection of the three asynchronous motors of kilowatts, speed and current? They are not the same at all, the triangle connection should be three times as powerful as the star connection. The motor is a star-shaped connection, and if you want to change it to a star-shaped connection, it becomes a kilowatt.

Its paraphrase is also fundamentally different.

It seems that you are casually talking about it, there are two connections marked on the nameplate, if the star connection power is one-third of the triangle, the nameplate will not be marked with this connection, it is contradictory to kilowatts.

Generally, it uses the triangle connection, because the efficiency of the triangle connection is relatively high, and whoever buys the motor is also about the efficiency and efficacy.

Summary. Hello, sir, in the rated voltage of 380V running three-phase asynchronous motor, the speed of the triangle connection and the star connection can be regarded as the same, the power difference is very large, for example, the triangle connection is a 10kw motor, running under the star, its power is only about 1 3 of the triangle. However, the power is equal to operate at 380*.

Hello, sir, in the rated voltage of 380V running three-phase asynchronous motor, the speed of the triangle connection and the star connection can be regarded as the same, the power difference is very large, for example, the triangle connection is a 10kw motor, running under the star, its power is only about 1 3 of the triangle. However, the power is equal to operate at 380*.

Hello sir, for a factory three-phase asynchronous motor, its speed is determined by the frequency of the power supply, the conversion connection method only changes the voltage of the motor winding, so the speed can reach the same in the no-load state, the load state is not auspicious, the heavier the load, the slower the speed.

Summary. Glad to be able to your questions.

The speed of the three-phase asynchronous motor is the same for the star connection and the triangle connection.

It's just that there is a difference in power and current, and the current of the triangle connection will be larger, which is equal to the line current. Due to the small starting output power, the star connection method is often used for small power, large torque motors, or large power motors at the beginning, so that the loss of the machine is small, and the triangle connection method is used after normal operation.

Hope mine can help you.

What are the differences between the star connection and the triangle connection of the kilowatt three-phase asynchronous motor, power, speed and current.

I'm glad to serve you, it takes about five minutes to sort out the answers, please wait patiently, a ray of happiness will be a good answer for you!

Glad to be able to your questions. The speed of the three-phase asynchronous motor is the same for the star connection and the triangle connection. It's just that there is a difference in power and current, and the current of the excited triangle connection will be larger, which is equal to the line current.

Due to the small starting output power, the star-shaped lead hall method is often used for small power, large torque motors, or large power motors at the beginning, so that the loss of the machine is small, and then the triangle connection method is used after normal operation. I hope my Hokure can help you.

Three-phase asynchronous motor delta connection and star connection power and speed is the same, in the rated voltage of 380V running three-phase asynchronous motor, triangle connection and star connection speed can be regarded as the same, the power difference is very large, for example, triangle connection for 10kw motor, running under the star, its power is only about 1 3 of triangle. However, the power is equal to operate at 380*. Hope it helps.