Forward and reverse connection method of two-phase motor

Two-phase motor, that is, one-way motor in single-phase motor, usually has a larger wire diameter, smaller resistance and fewer turns. However, some positive and negative single-phase motors do not distinguish between primary winding and secondary winding. ?

The connection is as follows:

In the last two pictures, a general conventional single-phase motor can be used, regardless of whether the parameters of its main coil and auxiliary coil are the same or different.

In addition, there is a kind of single-phase motor, which needs forward and reverse rotation in operation, but it is more troublesome to adopt the above method to realize automatic control and requires more devices, so there is a single-phase motor without primary and secondary windings, that is, the parameters of primary and secondary windings are the same.

Extended data:

In addition to the above methods, you can also do this.

Single-phase capacitor motor connection

A single-phase motor has three taps. First, measure the resistance between the three terminals with a multimeter. The two terminals with the largest resistance are connected in parallel, and the other terminal (male terminal) is connected to one end of the power supply. Then measure the resistance between the * * male terminal and the terminals at both ends of the capacitor with the electric block of the multimeter. The terminal with a slightly larger resistance is connected to the other end of the power supply, and it is absolutely connected to the forward rotation at one time. If you want to change the direction, you can change the power cord at one end of the capacitor to the other.

The main winding and auxiliary winding of three-wire single-phase generator are easy to judge:

1. First, measure the resistance of three wires in pairs, and remember the largest two wires and their resistance values. The third line is the connection point between the main line and the auxiliary line.

2. Measure the resistance values of the contact and both ends respectively (the sum of these two resistances must be equal to the above maximum value). Among them, the main winding has a smaller resistance, and the secondary winding has a larger resistance. Generally, for AC motors started by single-phase capacitors, the winding joint connected in series with the capacitors is the secondary winding. Let the secondary winding resistance be R 1 and the primary winding resistance be R2, then r1>; R2. (The main winding has high power and low resistance).

Measure and compare the resistance between two of the three terminals with a multimeter at one time. First, find the secondary winding connector terminal connected by live wire capacitor: the resistance between it and the other two terminals has the maximum value (series R2 R 1) and the second maximum value r 1). Among the remaining two terminals, find the one with the smallest resistance R2 and the second smallest resistance R 1, that is, the terminal connected to the zero line, that is, the common point of the main winding and the secondary winding.

Why does a single-phase motor have three starting capacitors connected to the motor?

If the motor itself has no wiring diagram, we can only measure three groups of resistances with a multimeter. The largest group has two terminals connected in series with the starting winding, the middle group has two terminals connected with the working winding, and the smaller group has two terminals on both sides of the starting winding. The working winding is connected in parallel with 220VAC, and the starting winding and capacitor are connected in series with the power supply.

References:

Baidu Encyclopedia-Practice Circuit Wiring