How does the star delta starter reduce starting current? Important Concepts
How does the star delta starter reduce starting current
The star delta starter reduce starting current by initially connecting the motor windings in a star configuration, which reduces the voltage applied to each winding. This reduces the starting current and torque. After a set time, the starter switches the windings to a delta configuration, allowing the motor to run at full voltage and power.
Table of Contents
Table of Contents
Factors Involved in Star Delta Starters
Here’s a more detailed explanation:
Reduced Voltage: When the motor starts, the windings are connected in a star configuration, reducing the voltage across each winding by a factor of 1.732 or square root of 3.
Current Reduction: The line current drawn by the motor at startup is reduced to one-third of the current if the windings were connected in delta. The starting current is reduced to 33% of what direct online starting consumes.
Torque Reduction: The torque developed by an induction motor is proportional to the square of the applied voltage. Therefore, the star delta starter reduces the starting torque to one-third compared to direct delta starting.
Components and Operation: Star-delta starters typically include contactors, a timer, and overload relays to control the switching between star and delta configurations. The timer ensures the motor accelerates progressively in the star connection before switching to the delta configuration. Learn more about Star Delta Starter Diagram with Timer.
Transition: During the transition from star to delta, there is a brief open transition state where the motor is connected neither in star nor in delta mode.
Suitability: Star-delta starters are suitable for motors that start with no load or have a low load torque with a progressive build-up.
Related Posts:
- What is star delta starter
- Star Delta Starter Diagram with Timer
- Overload Setting for Motor
- Difference Between Star Delta and DOL Starter
- Cable Size for Motor Calculator
- Induction Motor
Follow Us on Social:
Subscribe our Newsletter to get the latest updates in Electrical Engineering.
#StarDeltaStarter, #ReduceStartingCurrent, #MotorControl, #ElectricalEngineering, #StarDeltaStarterDiagram, #StartingCurrentReduction, #ElectricalDesign, #MotorStarter, #StarDeltaAdvantages, #ElectricalCircuits, #MotorProtection, #StarDeltaConnection, #ElectricalControlPanel, #PowerElectronics, #IndustrialAutomation