Star-Delta wiring diagram

Question

Accepted Answer

A star-delta wiring diagram is used to connect three-phase motors to the power supply.

Star-delta wiring is a method of connecting three-phase motors to reduce starting current and torque.
In star connection, the motor windings are connected in a star shape, while in delta connection, they are connected in a triangle shape.
During starting, the motor is connected in star configuration to reduce the current drawn from the power supply.
Once the motor reaches a certain speed, it is switched to delta configuration for normal operation.
Star-delta wiring is commonly used in industrial applications where high starting current can cause voltage drops or damage to the motor.

Accepted Answer

Most induction motors are started directly on line, but when very large motors are started that way, they cause a disturbance of voltage on the supply lines due to large starting current surges.To limit the starting current surge, large induction motors are started at reduced voltage and then have full supply voltage reconnected when they run up to near rotated speed.Two methods used for reduction of starting voltage are star delta starting and Auto transform starting

Star-Delta wiring diagram

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