PLC Program example No-2

Providing lubricant for the gear box before the lathe spindle starts to run which aims to ensure that the oil pump motor starts first and the main motor starts subsequently.

Number of PLC Inputs Required

X0 – START pushbutton to Start Oil Pump Motor

X1 – START pushbutton to Stop Main Motor

X2 – STOP pushbutton to Stop Oil Pump Motor

X3 – STOP pushbutton to Stop Main Motor

Number of PLC Outputs Required
            Y0 – Oil Pump Motor
            Y1 – Main Motor

PLC Ladder Programming:

PLC Ladder Programming Description:

•       This program is a typical application of the conditional control circuit. Y0 = ON when Oil Pump START button is pressed. Therefore, the oil pump will start to provide lube for the gear box of main motor(Y1)
•        Under the precondition of the operating state of the Oil pump, the main motor (Y1) will be ON when the Main motor START button is pressed.
•         During the operation of main motor (Y1), oil pump (Y0) needs to provide lube continuously.
•        The oil pump will be stopped when Oil pump STOP button X2 is activated, and the main motor will be stopped when Main motor STOP button X3 is activated.