The document outlines four PLC applications for controlling a 3 phase induction motor. The first application uses push buttons S1 and S2 to turn the motor on and off. The second application allows the motor to be turned on using either S3 or S4 and turned off using S1 or S2. The third application reverses the motor direction when S2 or S3 is pressed if S1 is pressed first. The fourth application reverses the motor direction by pressing S2 or S3 without needing to press S1 first.

1. PLC Applications
1- Turning an IM ON and OFF
A 3 ph motor has to be turned ON using the PB S2 and be turned OFF using PB S1.
Design a program to accomplish this task.

2. 2- Turning an IM ON and OFF from two places
A 3 ph motor can to be turned ON from two places using one of the push
buttons S3 or S4 and be turned OFF using either PB S1 or S2. Design a program
to accomplish this task.

3. 3- Reversing the direction of rotation of IM with stopping
Direction of rotation of a 3 ph motor can to be reversed by pressing one of the
pushbuttons S2 or S3 provided that the stopping PB S1 is pressed first. Design a
program to accomplish this task.

5. 4- Reversing the direction of rotation of IM without stopping
Direction of rotation of a 3 ph motor can to be reversed by pressing one of the
pushbuttons S2 or S3 without needing to press the stopping PB S1 first. Design a
program to accomplish this task.