When using ac motor appliances, any two phase sequences of the power supply can be adjusted mutually (called commutation) to realize the positive and negative adjustment of the ac motor.
Under normal circumstances, the V phase will not change. In order to ensure that the phase sequence of the ac motor can be interchanged when the two contactors are working, the U phase and W phase of the regulator remain unchanged. The top port connection of the contactor is as follows: maintain consistency when wiring, adjust the phase at the lower port of the contactor.
The reverse rotation of the brushless motor means that the phase angle of the brushless controller and the brushless motor are the same. Replace the wiring between the brushless motor and the A and C holes of the brushless controller, and connect the brushless motor and the brushless motor at the same time. It can be solved by replacing the main phase wires A and B of the brushless controller.
Since the phase sequence of the two phases is opposite, it is necessary to prevent the two KM coils from being energized at the same time. Otherwise, an interlocking device must be used, otherwise it will cause a serious phase-to-phase short-circuit fault. For safety reasons, double interlocking forward and reverse control circuits with button interlocking (mechanical) and contactor interlocking are usually used.
Button interlock, press the forward and reverse buttons at the same time, will not let the two phase-modulation contactors energize at the same time, mechanically avoiding phase-to-phase short circuit.
In addition, due to the use of contactor interlocking, the long closed contact cannot be closed as long as one of the contactors is energized. Therefore, in the application of electromechanical double interlocking, the 3-phase ac motor power supply system cannot be short-circuited. Circuitization This is to effectively protect the motor and avoid accidents such as phase-to-phase short circuit and contactor burnout during phase adjustment.
The line voltage between the L1 phase and the L3 phase of the 3 phase ac motor power supply is completely short-circuited by connecting the main contacts of the electromagnetic contactor. Therefore, excessive current will cause a short circuit and the circuit will be burned.
Therefore, the main contacts of the contactors KM1 and KM2 cannot be closed at the same time to prevent short-circuit accidents of the two-phase power supply.
The stepper motor needs to be directly driven by the driver. The upper part of the driver is the controller. The forward and reverse rotation of the stepper motor needs to be realized by the driver and the controller. The forward and reverse rotation is to control the specific steps of the stepper motor through the programming of the controller, including forward and reverse rotation, speed, walking distance, etc. The controller controls the positive and negative rotation of the stepper motor to drive the direction signal, but through positive and negative pulses. Some drives have a frequency generator, but this drive can be implemented by simply rotating the stepper motor back and forth according to the set speed without a controller.
Some friends may ask how to adjust the forward and reverse rotation of a single-phase motor. The start winding of a single-phase motor is connected in series with a suitable capacitor, and the two windings of the stator are automatically made by obtaining two rotating magnetic fields and a phase-shifting capacitor 90 degrees apart, which can be rotated.
To change the rotation direction of the motor, you need to find the start winding at the lead-out contact of the low rpm ac motor winding, and swap and connect one end of the original series capacitor and the other end of the original common point to change the direction of rotation. the goal of.
Yisenbao Motor: A professional manufacturer of ac motor appliances. Our motor products include 3 phase ac motor, low rpm ac motor, ac motor, and household appliances motor. Please contact us if necessary!
Recommended reading:
How to judge the forward and reverse of three phase ac motor?
