Can the star delta starting circuit save a main AC contactor

You can save a main AC contactor, but it is very unsafe, because in this case, as long as the circuit breaker is not disconnected, the coil of the motor will always be charged (including the 6 wires to the motor, as well as the main contacts of the star and triangle contactors are electrified), if someone repairs and does not close the main circuit breaker, a serious accident will occur, it is not recommended to save such a little money, I hope to be Thank you.

The method of the two contactors: the main circuit, the circuit breaker outlet is connected to the U1 V1 W1 of the motor and is connected in parallel to the inlet side of the triangle contactor at the same time, the U2 V2 W2 of the motor is connected to the outlet side of the triangle contactor, and at the same time it is connected in parallel to the star contactor T2 T4 T6 The star contactor T1 T3 T5 is shorted and can be started and run normally, but the disadvantages are obvious as mentioned above.

That is, the motor has been charged, so how can it protect the motor? Especially when it comes to interphase breakdown.

Star delta is a more classic step-down start, can not save the contactor, the motor lead-out wire 6 taps, one less main contactor will cause the motor to not run normally, because he relies on the contactor to connect the 6 taps into a star, in the conversion into an angle, to achieve step-down start (now a lot of information is shared, the general trend is ah, but good things are still charged).

No, if you save it, it's not a star triangle.

Depending on the situation of the design circuit, it is generally not possible.

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.

When starting, the KM1, KM3 closed motors are star-wired. Triangle.

Operation, km3 disconnection, talk about km2 closed with grinding base and swim block.

In the figure, KT is the startup time timer, which is used to set the startup time.

The 6 wires of the Star-delta starting motor are connected to the AC contactor, as shown in the figure below: In the figure: QC - the main contactor for starting.

YC--Star Contactor for starting. SC - Angular Star Contactor for Operation. The number on the motor graphic represents the 6 terminal blocks of the motor.

Arranged in a clockwise direction from 1 to 6. Note: 1. Before wiring, the motor windings and the windings and shells must be checked to prove that they are in good condition before they can be put into use.

2. Before wiring, the actual end number of each terminal of the motor winding must be distinguished, and there must be no mistakes! 3. The specific data of each component in the figure should be configured according to the actual power of the motor. Extended data installation conditions 1, the altitude does not exceed 2000m; 2. The upper limit of the ambient air temperature shall not exceed +40, and the lower limit shall not be less than -5; 3. The relative humidity of the air at the installation site does not exceed 50% at the maximum temperature of +40, and can have higher relative humidity at lower temperatures, the average minimum temperature of the wettest month does not exceed +25, and the average maximum relative humidity of the month does not exceed 90%.

Measures must be taken due to the condensation of the product due to temperature changes; 4. The installation inclination with the vertical plane should not exceed 5°; 5. Pollution level: level 3; 6. In a place where there is no significant shaking, shock and vibration. Structural characteristics 1: The contactor is equipped with a current limiting resistor, which can suppress the inrush current of the closing within the allowable range. 2. The contactor is a direct-acting double-break structure, with flexible action mechanism, convenient manual inspection, compact structure, and convenient contact replacement; 3. The terminal of the contactor is covered by an insulating cover, which is safe and reliable; 4. The installation can be fastened with screws, or it can be buckled on the 35mm standard installation track.

22kw motor with star delta start, how big to choose AC contactor.

Hello dear, you can choose 50 or 60 amp contactors and relays. How big contactor and thermal protection relay for 22kw motor star-delta starting22kw motor adopts star-delta starting, the rated current of the thermal protection relay and contactor should be selected after calculation by electrician. According to P 3 u i cos, the rated current:

i=p 3 u cos =22 amperes) Considering the influence of the starting current on the AC contactor and thermal relay when starting the motor, the reliability coefficient is optional, then the current of the contactor and thermal relay should be set as: i1= ampere leakage loss socks, the actual market does not have the current of the contactor and relay, you can choose 50 or 60 amperes contactor and relay; The operating current of the thermal relay can be realized by adjusting the knob according to the nature of the load and the difficulty of starting the motor. Due to the small size of the motor and the short start-up time, the operating current of the thermal relay can avoid the influence of the starting current.

Generally, the contactor is selected according to the multiple of the rated current of the restart, or the empty spring is selected according to the following experience: 1) continuous operation.

Good morning, dear, first of all, it needs to be clear that the star-delta forward rotation of the AC contactor refers to the use of 4 AC contactors on the switcher to achieve forward start when the AC motor uses the star-delta starting method. If the AC contactor is not working properly and the forward start cannot be achieved, the possible reasons include:1

Poor or damaged contactor contact. 2.The fuse in the rise-controlled guessing circuit is blown out.

3.The power supply voltage is abnormal or insufficient, resulting in the contactor being unable to engage the high bond normally. 4.

Control relay failure. Therefore, you can follow the steps below to troubleshoot and solve:1

Check whether the fuses in the contactor and control circuit are normal. 2.Check whether the power supply voltage meets the requirements.

3.Test whether the contactor can be properly engaged, and if there is a poor or unstable attachment, the contactor needs to be replaced or repaired. 4.

Check whether the control relay is faulty, and if there is a problem, the control relay needs to be replaced or repaired. Tips; If none of the above methods solve the problem, it is recommended that you seek professional help.

Pro-this-box, star-delta starting is a common way to start an AC motor, which needs to be controlled by an AC contactor during its operation. The following are the star-delta forward rotation steps of 4 AC joint sock contactors:1

Connect the three motor cables to the three output terminals of the AC contactor. 2.Connect the control circuit of the Jiaoqing current contactor to the main power supply.

3.Turn on the main power supply, the AC contactor will automatically switch to the star state, and the motor will run at low voltage when it is positive. 4.

Wait for a while for the motor to accelerate to full speed and check the normal operation status of the motor. 5.When the motor reaches a predetermined maximum speed, switch the AC contactor to a triangular state and the motor will continue to run at full speed.

6.Monitor the load and performance of the motor to ensure proper operation. Kiss:

The above is the forward rotation step, and the wiring method needs to be adjusted according to the actual situation when reversing.

22kw motor with star delta start, how big to choose AC contactor.

The first step: calculate the rated current value of the motor The first algorithm: quick estimation, calculated according to the 2 currents of kilowatt power, 22kw 2=44a, that is, the working current of the 22 kilowatt motor is 44A The second algorithm, the formula is calculated:

Working current = power (voltage power factor) = 22000 (380, that is, the working current of the 22 kilowatt motor is 42A For the above two algorithms, the data calculated by the imitation is not much different, so the calculation of the working current of the motor can be calculated in accordance with the estimation method, simple and quick Note: The motor belongs to the inductive load, so the calculation of the working current should take into account the power factor, the power factor is generally between, if you don't know, take it to calculate the second step: configure the air switch, the air switch is divided into 4 series, respectively A, B, C and D, A and B are not commonly used, the most commonly used is C type and D type, C type is used for household electricity, D type is used for power electricity, so the 22 kilowatt motor should be equipped with D type air switch 22KW motor configuration air switch, to be configured according to the multiple of the motor working current, so to configure 52A 66A air switch, we can choose D63 air switch The third step is to configure AC contactor motor configuration AC contactor, To be configured according to the multiple of the working current of the closed motor, the working code of the motor is 44A, so to configure the AC contactor greater than 66A and closest to 66A, we can choose the 65A contactor.