A dual starter connects the motor terminals directly to the power supplyhence the motor is subjected to the full voltage of the power supplyconsequently high starting current flows through the motor. The power circuit uses to create contact between the motor and three phase power supply.

Read Wiring Diagram Star Delta
Star delta starter diagram pdf download. Star delta starter can be used only for low to high power three phase induction motors. Siemens star delta starter wiring diagram pdf. The direct on line motor starter dol consist a mccb or circuit breaker contactor and an overload relay for protection. Control circuit devices for star delta starting 8 45 pole changing motors 8 47 motor windings 8 50 multi speed contactors 8 53 multi speed switch for three phase motors 8 55 control circuit devices for multi speed contactors 8 63 multi speed switch for three phase motors 8 68 three phase autotransformer starter 8 83. Star delta connection circuit diagram. This equipmentappliance reduces starting current and starting torque.
Ladder diagram of star delta starterpdf free download ebook handbook textbook user guide pdf files on the internet quickly and easily. The peak starting current is 13 to 26 of full load current. Refer to the below star delta circuit. Download full pdf circuit diagram 1 download full pdf circuit diagram 2 note. Star delta connection diagram and working principle. The control circuit uses to control the starter circuit such as on off and tripping operations.
The peak starting torque is 33 of full load torque. The starting current is 33 of full load current for star delta starter. In the diagram of power circuit of star delta starter u2 and v2 of 3 phase motor should be connect to 4 and 6 respectively instead of u2 and v2 are connected to 6 and 4 of delta contector km2. Siemens sirius 3rt pdf user manuals. Characteristics features of star delta starter. Lathes millers grinders shapers borers and other machine tool instruction operation and maintenance manuals handbooks and parts manuals.
This is one of circuit diagram design for star deltait have variant design of star delta diagram depend on designer style for motor controlthe important thing is it can operated with correct sequence and operation to avoid motor from serious damage or burn out. Star delta starters consist of a power circuit and control circuit. This type of starting is suitable for small motors below 5 hp 375 kw. Automatic star delta starter design normally consists of three contactors an overload relay or circuit breaker and a timer for setting the time in the star position starting. A star delta starter is a type of reduced voltage starterwe use it to reduce the starting current of the motor without using any external device or apparatus. This is a big advantage of a star delta starter as it typically has around 13 of the inrush current compared to a dol starter.
There is minor correction is require to change printed in boxes sequence of 3 phase wires from w2 v2 u2 to w2 u2 v2 to get delta connection properly.