The problem of forward and reverse rotation of 380V motor, what happens if the three phase motor has

The three-phase AC asynchronous motor can be reversed by adjusting any two phase wires.

Yes, but you look at its settings, there is no forward and reverse switch, you just need to swap any two of the incoming wires, the motor is not reversible but some motors are reversed is wrong.

In the case of a three-phase AC asynchronous motor, it is possible to reverse it by this method.

Theoretically, three-phase AC asynchronous motors can be reversed through commutation, regardless of whether they are star or triangle.

The DC motor can change the excitation supply polarity or armature supply polarity to achieve reverse rotation.

Three-phase motor. What's going on with a forward and no reversal?

It depends on whether the control circuit has the function of forward and reverse rotation.

If the control circuit itself does not provide the reversal function, then the motor will not reverse.

If the control circuit has the function of forward and reverse, and the TV does not reverse, it is the control circuit is faulty. Once the fault is eliminated, the motor can be reversed.

The three-phase motor has forward and reverse rotation, and the phase of the connected live wire is not correct if the reversal is not used.

The phases of the three-phase electricity U, V, and W are 0 degrees (or 360 degrees), 120 degrees, and 240 degrees respectively. If the phase sequence is not right, the steering will be different.

The three-phase motor has forward rotation and no reversal, which is your reverse AC contactor and does not change the phase sequence (the reverse AC contactor does not work or the contact is poor), so there is no reversal.

The three-phase motor has a forward and reverse rotation control device, which can check whether the conversion contacts are in good contact. Whether the wiring is intact and has not fallen off. Some equipment is not allowed to reverse, and there is a "reverse stop" device inside the motor, which can be found by disassembling the motor.

The possible reason is that there is a problem with the line responsible for the reversal of the motor, and it is a matter of minutes to ask an electrician to repair this problem.

The reason why the three motors can rotate forward and not reverse is to determine whether the direction of line current is normal.

Three-phase motors include synchronous motors and asynchronous motors.

Three-phase asynchronous motor has forward and reverse rotation;

The synchronous motor is not reversed, and what you buy is a three-phase synchronous motor.

Is there such a situation? I haven't seen it before. Invert the root line to see what the situation is.

In order to ensure that the phase sequence of the motor can be reliably changed when the two contactors act, the upper wiring of the contactor should be consistent, and the lower mouth of the contactor should be phase-adjusted. The advantage of forward and reverse rotation control of three-phase motor is that it works safely and reliably.

The disadvantage is that the operation is inconvenient, because when the motor is transformed from forward to reverse, the stop button must be pressed before the reverse start button can be pressed, otherwise the reversal cannot be achieved due to the interlocking effect of the contactor. In order to overcome the shortcomings of this line, the forward and reverse control line of button interlock or double interlock of button and contactor can be adopted.

Summary. The reversal of the 220V motor is generally connected to the wrong wire, so you can try to reverse the two ends of the power supply to troubleshoot. According to the principle of the motor, the 220V motor can realize the forward and reverse rotation of the motor by reversing the power supply.

The two-phase motor of the 220V motor has reverse rotation, there are two windings are divided into positive winding and auxiliary winding, the positive winding has U1 U2 represents two heads, the secondary winding has V1V2 representative, the forward rotation U1V1 is connected together, the L line is drawn, the L2 line is drawn out, and the capacitance is connected between U2V2. Invert U1V2 together, and connect capacitors between U2V1.

What to do if the 220v motor is reversed.

The reversal of the 220V motor is generally connected to the wrong wire, so you can try to reverse the two ends of the power supply to carry out a round check. According to the principle of the motor, the 220V motor can realize the forward and reverse rotation of the motor by reversing the power supply. The two-phase motor of the 220V motor has a reverse radical turn, there are two windings are divided into positive winding and sub winding, the positive winding has U1 U2 represents two heads, the secondary winding has V1V2 representative, the forward rotation U1V1 is connected together, the L line is clearly known, the L2 leads out the N line, and the capacitor is connected between U2V2.

Invert U1V2 together, and connect capacitors between U2V1.

Is it enough to flip over these two threads?

Theoretically, it is.

Thanks, I'll give it a try.

Don't regret it, if you are satisfied with my service before Wang Wu, Ma Ma Zai annoys to give a thumbs up, thank you. 

It's not right, it's still reversed.

If this can't be solved, it is an internal problem of the motor. This cannot be solved by wiring.

Okay, thanks, I'll let the motor repair it. Okay.

Categories: Education Science >> Science & Technology >> Engineering Technology Science Problem Description:

One of our company's cranes can only go north and not south, the main thing is that the contactor that goes south is pressed and the button is not sucked, and there was this problem yesterday, so a new contactor was replaced. But when you press the button, it only hums. The contactor is not suctioned, the line should be good, and he can go south with a screwdriver to get the suction part of the contactor, but the switch is useless, and I don't know what the reason is.

Please tell me the reasons that may cause this failure, hehe, I am an outside line electrician, and I am not very qualified, hehe, the leader told me to repair. I didn't do it for a long time. Thanks, there is a workaround.

Analysis: The forward and reverse rotation of the motor is actually to switch the three-phase power line, usually through two contactors, at the upper end of the contactor, the power line of any two phases is reversed, and at the lower end of the contactor, the contacts at the same position can be connected in parallel. In the control circuit, the two contactors should be interlocked, that is, the normally open contact of one contactor should be connected in series in the control loop of the other contactor to prevent the forward and reverse rotation from being started at the same time, resulting in a short circuit of the power supply and danger.

One end of the coil of the contactor should be connected with the one press chamber button (forward) through the normally open contact of another contactor, and the other is also, one end of the coil of the contactor should pass through the normally open contact of another contactor and a button (backward), then the other end of the button is connected together by a wire, and the normally closed contact of the stop button is connected to the power supply.

Reference circuit diagram;