Single-phase asynchronous motor forward and reverse wiring method Single-phase asynchronous motor capacitor wiring method

Single-phase asynchronous motor forward and reverse wiring method

Single-phase asynchronous motor is a type of motor powered by 220V single-phase AC power supply. It is suitable for small industrial equipment and household appliances with only single-phase power supply.

The most commonly used single-phase asynchronous motor is the capacitor split-phase type. The motor has two windings, and the starting capacitor is connected in series with one of the capacitors, so that the magnetic field generated by the two windings after power is turned on has a 90-degree phase difference, so that the rotor gets the rotation torque and rotates. Therefore, the forward and reverse control of the motor is achieved by changing the phase difference between the windings.

Prepare tool components and connect them according to the circuit diagram.

Wiring Instructions:

Connection diagram of forward and reverse switch and motor (attached picture), the red and blue wires are connected to the power supply, the black wire is the lead wire of the starting winding coil, the white wire is the lead wire of the running winding coil, and the gray wire on the left is the jumper wire connected later. The forward and reverse reversal is reversed by the cross-connector of the switch.

The shortcoming of this type of switch is that after the switch is turned off, there is still a wire that is not turned off, so there is no certain guarantee of safety.

According to the circuit diagram, check the wiring is correct.

Turn on the power and conduct a test run.

Capacitor wiring method for single-phase asynchronous motor

Split-phase operation: The auxiliary operation winding is used to assist the operation, and the operation torque is not large. The operation speed is roughly constant. It is mainly used in electric fans, automobile cooling fan motors, automatic washing machines and other motors.

When the motor is stationary, the filter switch is connected. After power is supplied, the starting capacitor participates in the operation. When the motor rotor speed reaches 70% to 80% of the rated current, the filter switch will automatically disconnect, the starting capacitor reaches its target and is disconnected. The running capacitor is connected in series with the running winding to participate in the operation. This wiring method is generally used in areas with large and unstable loads such as air compressors, automatic cutting machines, and woodworking machine tools.

The 380V single-phase dual-capacitor motor has a starting capacitor and a running capacitor. The larger one is the starting capacitor, and the smaller one is the running capacitor. After the motor is running, the power switch disconnects the starting capacitor from the power circuit.

If the starting capacitor is missing, the motor will run hard or fail to start (often manifested as normal operation at full load, but unable to start after loading); if the running capacitor is missing, the motor can run, but the power is reduced (often manifested as reduced load capacity). Generally, the starting capacitor is connected in series to the running winding of the DC motor, and in series with the working winding.

Wiring diagram of a single-phase asynchronous motor with three wires connected to a capacitor: The motors are different. Find the common terminal (main power line terminal). Use a multimeter to measure the resistance between the other two wires and the common terminal. The resistance of the two sets of coils, whichever has the larger resistance (starting winding), is connected to the capacitor. The common terminal and the end with the smaller resistance (working winding) are connected to the power supply.

A red test lead touches one of the wires, and a black test lead touches the other two wires respectively. If the resistance of the two wires is not much different, the red test lead is the common terminal. Assuming that the resistance of the two wires differs by one times, the remaining one is the common terminal.

Generally, the blue or white (sometimes green) is the common terminal (live wire). The yellow and the other color wire (neutral wire) are connected to the capacitor.