Hand-operated star-delta starters

Features

• Power range: 4.0 - 9.0 kW - Higher powers on request
• Inrush current limitation when starting asynchronous motors
• Reduction of inrush current to 1/3 of the value during direct starting, considering the acceleration time
• Various designs available
• Manual operation

Star-delta starters are used for asynchronous motors starting at 4 kW to prevent excessively high inrush currents during startup. The limit values are usually set by the utility companies.

The simplest design of a star-delta switching is realized with a cam switch. The switching from 0 to star and to delta is done manually by the operator. To avoid unwanted voltage spikes, at least 80% of the nominal speed must be reached when switching from star to delta. When connecting the motor, care must be taken to ensure the suitable motor nominal voltage.

A motor suitable for star-delta starting must have a voltage output of 380V / 660V or delta 380V at a mains voltage of 380V. For connection, motors with 6 outgoing winding ends are required.

These star-delta starters are equipped with overload protection. This is wired in series. For the design of the overload protection, the motor nominal current must therefore be multiplied by 0.58. A motor nominal current of, for example, 16A results in a setting value for the overload protection of 9.28A.