Programmable Logic Controller Set for Complete Operation and Monitoring of Protection Interlock for Circulating Water Pump House

This paper introduces the basics of a Programmable Logic Controller (PLC). It details the architecture and basic instruction set common to all PLC’s. Basic programming techniques and logic designs are covered. This Paper describes the operating features of the PLC, the advantages of the PLC over hardwired control systems, practical applications, troubleshooting and maintenance of PLC’s. In Power plant operation PLC plays an important role for the Automation of System. Nowadays Power industry is experiencing many changes. One of the many developments is in the field of Automation with less interference of human being. Automation in Power industry would be useful for safety of Power plant. It increases the efficiency of the system in terms of speed, reliability, cost effectiveness, flexibility. PLC found its application in the operation of the Pumps, all auxiliaries / drives and Discharge Butter Fly Valves including motor operated Duct Interconnecting Valves. All the logic of permissive and interlocks for the operation of Circulating Water(CW) Pumps and Butter Fly Valves will be performed at PLC in Control Room. Start, stop, open , close command will be issued from Control Desk to Master Control Centre / Switchgear Via Programmable Logic Controller(PLC).All the interface signals from Limit & Torque Switches of Pump Discharge Butter Fly Valve shall be made available at PLC.