15KW three phase 380V star delta starter contactor with how many A

Contactors are made with 30A or 32A.

The current of the 15kw motor is generally less than 30A, and the specific value depends on the number of stages of the motor. You can choose 30A air opening, 32A for the two main contactors, 16A for the star point, 32A for the thermal relay, and the time relay is generally selected within 1 minute, and the setting time is about 10 seconds, depending on the load characteristics, and it is advisable to convert it to 2-3 seconds after the starting current is stable.

40aThe star-shaped starter contactor is used for 25A to 30A, the running current of the motor is 29A, the setting current of the thermal overload is multiple of the operating current, and the setting current of the fuse is 5 to 6 times of the running current.

First, the star angle step-down start of the motor.

When the load has no strict requirements for the starting torque of the motor and the starting current of the motor is limited, the motor meets the wiring conditions of 380V δ, and the stator winding is connected into a triangle when the motor is in normal operation.

There are six external terminals in the three-phase winding of the motor with star-delta step-down start: A-X, B-Y, C-Z (the following takes the motor with a rated voltage of 380V as an example).

a.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.

b.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 converts the six terminals into a triangle connection and connects to the 380V power supply again, when the winding voltage of each phase is 380V, the torque and speed are greatly improved, and the motor enters the operation process under rated conditions.

Second, the choice of 15kw three-phase motor star-delta start-up contactor.

When the motor is triangular during normal operation, the power calculation formula: p=, the power factor cos is taken, then: i=15000 (

Therefore, the contact contactor is selected as 30A 50A

A contactor direct start is 30 50A, generally 50A, Star Delta start is the motor out of 6 lines, 2 contactors work at the same time, each contactor current is only half of the direct start, 3210 is more than enough!

Dear, hello, I'm glad to answer for you, how big is the contactor for 75kw star triangle rock leakage starter is 80a contactor for 75kw motor star triangle start. The rated current of a 75kw motor is calculated to be about 75000 380. When the motor is running, it is jointly loaded by the main contactor and the triangle contact, and the current of each load is 134 2=72A.

The rated current of the contactor is selected to be about multiple of the rated current of the motor, then 72*. Therefore, it is possible to choose a contactor with a rated current of 80A. Star-triangle starts to move with three contactors, among them, the main contactor and the triangle contactor have the same specification (this question is 80a), and the star-shaped contactor can be one size smaller, and the choice is to use 63a to connect the wheel contactor.

However, it is recommended to connect the buck coil in series during start-up.

For the 22KW motor, a thermal relay with a setting current between 24 and 32A can be selected.

The models of 22KW motor star-delta starting contactor can be selected: CJX2-4011, CJX2-5011, CJX2-6511, CJX2-3201, CJX2-3210 or other 32-65A specifications.

Suppose it is a standard 4-pole 50Hz, 1500 rpm squirrel cage asynchronous motor in the case of AC380V, then its rated current is in, if the motor current is 50A or more, then it needs to be calculated again.

When starting, the current is 1 3, that is, the current of the km1 contact chain key device is greater than that, so you can choose a 16A contactor.

KM2 and KM3 are long-term operation in a triangular circuit, so their current is, so these two contactors can be selected to be greater than that.

The normal operating current of the 45kw motor is 45*2=90A, the contactor of 100 is enough, and the life of the contactor is longer with a large point contactor, and the starting current is about 90 3*2, about 60A, so the star AC is about 60A.

The principle of star-delta starting of the motor is to apply different voltages to the three-phase windings of the motor during start-up and normal operation to reduce the impulse current when the motor is started.

At the time of starting, the power supply of the star connection method is applied to the motor winding, that is, the three live wires of the power supply are connected with one end of the three windings of the motor respectively, and the other end of the three windings of the motor is connected with the neutral line of the power supply at the same time, and under this connection, the voltage that each winding of the motor undertakes is 220V.

Summary. How big are the three contactors used for the motor star-delta starter?

Hello dear, the contactor selection of the motor:

According to the rated current of the motor of 33A, the two contactors running at full voltage are selected as 40A, and the contactors of the neutral point short circuit are selected as 32A, that is, two 40A and one 32A.

The current of the motor: i=p u i=18500 380 How big are the three contactors used for the star triangle starter of the motor?

How big are the three contactors used for the motor star-delta starter? Hello back to the start, the contactor selection of the motor: three contactors on the step-down start, according to the rated current of the motor 33A, the full pressure operation of the slow Shisui two contactors choose 40A, the neutral point short contactor selection of 32A, that is, the current of two 40 A and a 32A motor

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Summary. 55kw motor star delta starter with 160A contactor.

When the delta step-down starts, the starting current is much smaller than the start-up current at full voltage, which is theoretically one-third of the step-down start-up time, and about 2 times the rated current. Therefore, the rated current specification of the three contactors in the circuit can be less than the value at full voltage start-up. According to the circuit diagram, the main contactor and the angle sealing contactor are both bearing the phase current, so the contactors of the same specification are used, and they are generally selected according to the multiple of the phase current.

55kw motor star delta starter for multi-size contactor.

55kw motor star delta starter with 160A contactor. When the star-delta step-down starts, the starting current is much smaller than the start-up current at full voltage, which is theoretically one-third of the dissipation wheel when the step-down starts, or about 2 times the rated current. Therefore, the rated current specification of the three contactors in the circuit can be less than the value at full voltage start-up.

According to the circuit diagram, the main contactor and the angle sealing contactor are both bearing the phase current, so the group letter used is the contactor of the same specification, and it is generally selected according to the multiple of the phase current.

If I can help you, that will be my greatest joy! Thank you very much!

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This method is okay, can you try it?

Summary. The contactor is divided into two situations, the current of the contactor as a triangle connection is about 37*2 74A, and then check the manual of the product model, and the selected model can include 74A. As a star connection, the contactor should have a current of 74 No. 3 43A, the same as before, 43A can be included in the range of selection.

The rated current and the rated current of the motor can be consistent. Choose 100a.

The contactor is divided into two situations, the contactor current as a triangle connection is about 37 * 2 74A, and then go to the Liangtong family to check the manual of the product model, and the selected model includes 74A in it. As a star connection, the contactor should have a current of 74 No. 3 43A, the same as before, 43A can be included in the range of selection. The rated current rotation and the rated current of the motor can be consistent.

Choose 100a.

The star-delta judgment of the motor starter contactor selection method is typical star-delta starter, there are three contactors, the main contactor, the angle contactor and the star contactor, how to choose these three contactors? First of all, the theoretical analysis is as follows: 1. When the triangle works, the phase current i (phase) = u(n) z z is the reactance line current of each phase winding i (line) = i (phase) * 3 u (n) is the voltage of the local stove beam of the power grid 2, when the star is working, the line current i (line) ' = phase current i (phase)' = u(n) 3 z For the motor that works normally as a triangle, its rated current is the line current when the triangle works, and if the motor is in a star-shaped operation, its working current is the line current i (line)'=Phase current i (phase)' = u(n) 3 z= i (phase) 3= i (line) 3 3= i (line) 3 that is, the line current when the star is working in the triangle is 1 3 For example, a 55kw motor, the rated current is 105A, which requires the star angle to start.

If the main contactor is connected to the main circuit and the angle contactor is connected to the phase circuit, the current flowing through the main contactor of Tongyun is 105A when the triangle is working, and the contactor of 110A is selected; The current flowing through the angle contactor is 1 3 of the rated current, which is about 105 3 = 60A, and it is enough to choose a contactor of 63A. The working current of the star working is 1 3 of the rated current of the motor, that is, 105 3 = 35A, so it is enough to choose 40A for the star contactor.