This lesson is a continuation of our instruction on the use of star delta plc programming and wiring series. Jan 12 2019 motor contactors are controlled by using plc.
Basic Plc Program For Control Of A Three Phase Ac Motor
Star delta starter plc ladder diagram pdf. When electric motor is started it draws a high current typical 5 6 times greater than normal current. The star delta starter is a common method used in starting heavy three. We will go into greater detail about what safeguards we want to add to the program to. In dc motors there is no back emf at starting therefore initial current is very high as compared to the normal current. Ladder diagram of stardelta starter with a mitsubishi plc. Ladder diagram of star delta starterpdf free download ebook handbook textbook user guide pdf files on the internet quickly and easily.
The following section of plc tutorial will explain the ladder programming for star delta motor starter. Characteristics features of 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. To protect the motor from these high starting currents we use a star and delta starter. The peak starting current is 13 to 26 of full load current. Plc based star delta starter for starting and direction control of three phase induction motor.
Another great example of how to use a plc for stardelta start of an ac motor is example 5 in the pdf file below. 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. It is found that a great flexibility is available in plc programming as any sort of changes can be done. The time of forward rotation and backward rotation is controlled using timers in the ladder diagram program. The ladder logic for a stardelta motor control is quite simple and that is one of the advantages of using a plc for motor control. Star delta starter can be used only for low to high power three phase induction motors.
The starting current is 33 of full load current for star delta starter. The peak starting torque is 33 of full load torque.
Gallery of Star Delta Starter Plc Ladder Diagram Pdf
