1, star connection: star connection refers to connecting the three-phase ends of the motor winding together, the first end of the three-phase is the power supply end, and the output voltage is 220V V V. Star connection is often used to start a motor with low power and high torque, or a motor with high power. Because of its low starting and output power, the machine loss is small.

2. Triangular connection: Triangular connection refers to connecting three-phase windings end to end, with three terminals as power terminals and an output voltage of 380V V V. Generally, triangular connection is only used after the motor starts to work normally.

3. In triangle connection, each winding of three-phase motor bears line voltage (380V), and in star connection, each motor bears phase voltage (220V). Under the condition of the same motor power, the winding current of angle wire motor is smaller than that of star-connected motor.

Extended data:

Triangular connection

The triangular connection of the motor is to connect the windings of each phase end to end in turn, and lead each connection point into a three-phase line of three-phase electricity. The phase voltage of the motor is equal to the line voltage when the triangle connection is made; The line current is equal to three times the root phase current.

star connection scheme

The star connection of the motor is to connect one end of each phase winding to a point, and the other end of each phase winding is used as a lead-out wire, which is a three-phase wire respectively. In star connection, the line voltage is three times the square root of the phase voltage and the line current is equal to the phase current.

Star connection is often used to start a motor with low power and high torque, or a motor with high power. Because of its small starting and output power, the loss caused to the machine is small, so triangle connection is adopted after normal operation. This is the star that is often mentioned-the triangle star.

Selection of motor connection

It is a three-phase motor, and a single-phase motor does not have the above two connections. Generally, there are more star connections for motors below 3KW, and more angular connections for motors above 3 kW. According to the regulations, motors larger than 15kw need star-shaped starting angle to reduce the starting current.

There is also a small motor that starts at an angle. If you want to connect to the three-phase 220V supply voltage, you must connect to the star.

Three-phase electricity has two connection modes: star connection and triangle connection. Both connections have three three-phase power lines and three power sources (or loads), but the power sources (or loads) are connected in different ways.

The voltage in the three-phase four-wire system in the daily power consumption system is 380/220V, that is, the phase voltage is 380V, and the phase voltage varies with the connection mode; If star connection is used, the line voltage is 220V, and the phase voltage of triangle connection is 380V V. ..

References:

Baidu encyclopedia-three-phase alternating current