1. Voltage Rating: HT motors are designed to handle higher voltage levels, usually above 600V. Connecting the motor in star configuration reduces the voltage applied to each winding by a factor of √3 (approximately 1.73). This ensures that the voltage stresses on the motor's windings are within acceptable limits and prevents insulation failure.
2. Current Distribution: When an HT motor is connected in star, the current is evenly distributed among the three windings. This balanced current flow reduces the heating effect in the motor windings, resulting in higher efficiency and improved motor lifespan.
3. Power Factor: Operating an HT motor in star connection improves its power factor compared to delta connection. A higher power factor means more efficient utilization of electrical power and reduced power losses in the motor.
4. Starting Torque: Star connection provides a higher starting torque compared to delta connection. This is advantageous for HT motors that need to overcome high inertia loads or start under heavy load conditions.
5. Reduced Voltage Starting: Star connection allows for reduced voltage starting methods, such as star-delta starting or autotransformer starting. These methods are commonly used for HT motors to limit the high inrush current during motor startup and reduce mechanical stresses on the motor's components.
6. Protection: Star connection provides better protection for the motor against phase-to-phase faults or short circuits. In case of a phase fault, the motor can continue to operate with reduced power on the remaining two healthy phases.
7. Standard Manufacturing: Most HT motors are manufactured and designed to be operated in star connection. Rewiring them for delta connection may require additional modifications or rewinding, which can be complex and time-consuming.
It's important to follow the manufacturer's recommendations for the specific HT motor regarding its connection configuration and operating parameters to ensure safe and efficient operation.
