An Energy-Savings Evaluation Method for Variable-Frequency-Drive Applications on Water Pump Systems

This paper presents the design and control system of a motor for reduction energy and water loss in the water supply pump systems by using PLC with variable speed drives. A motor is a device that uses a high percentage of energy in both buildings and in industrial plants. Most of these motors operate at constant speed all the time. Where the load or power demand from the motor changes according to the actual usage needs. Adjusting the motor speed to suit the work load each time can save energy. Using a variable speed drive (VSD) device with a pump is one convenient way to save money, generally it will reduce the energy consumption by about 15 - 20% of the energy used. As during the period when there is no water usage or low water usage will cause a burden of the electricity that is used undue and unnecessary water loss (10 - 15% of total flow). Therefore, from this research topic, we focus on analyzing the method of saving electricity and reduction of water loss that occurs in the system. This will reduce unnecessary expenses and generate income to the organization by using variable speed drive (VSD) and PLC.