Automatic operation and control of air compressor system using plc

1. INTRODUCTION In order to automate a process system and to minimize human intervention, PLC based system will be a good option that monitor the system and help to reduce the error caused by human. The wide applications of PLC in many areas have significantly contributed to the operation and automatic control of electrical and electronic system [1-2]. In this study the operation and control features of a air compressor system is categorized in three phases: Firstly, compressor startup without load and check all protection features, Secondly, If all protection and operating condition fulfilled then compressor running under load, Finally, synchronize with the demand that is if demand is full, running at hundred percent load and if demand is low, running at fifty percent load. In first phase, if all the protection features of air compressor start up are silent condition and all the alarm are reset state only then compressor motor will start-up. The second phase covers mainly all the mechanical protections of the compressor such as checking the lube oil pressure, cooling water flow and air temperature. If any protection or safety feature fails then compressor will tripped. In the third phase, synchronize with the demand and corresponding to the demand load varying between fifty and hundred percent. Thus the entire cycle is carried out at various stages and each phase is detailed out in this study. Similar PLC based automation systems are also widely used to monitor and control plants or equipment in industries such as power plants, energy, oil and gas refining and transportation [5-8].