Energy saving drives: savings are not only from motor speed controlIt is generally accepted that installing AC variable speed drives in fan, pump and compressor installations offers significant energy saving, reducing cost and lowering CO2 emissions. However, all variable speed drives are not equal: some VSDs include advanced software that provides further savings, and provide compelling arguments for replacing inverter drives that were installed over ten years ago.Mitsubishi Electric has been designing, building and using inverter drives for both constant and variable torque application for over thirty years. It also makes many of the semi-conductors used in modern drives, and this gives them a significant advantage over many other manufacturers.With their recently introduced F800 Series inverter drives Mitsubishi claims it to be the enhanced next generation of energy saving inverters, designed specifically for building and HVAC application. It offers enhanced energy savings, improved operating characteristics, better safety, and simpler installation and diagnostics.The consumed power of a variable-torque load, such as fans, pumps, and blowers, is proportional to the cube of its rotation speed. Adjusting the air volume by the inverter rotation speed control can lead to energy savings.Getting more out of the motorsOptimum excitation control continuously adjusts the excitation current to an optimum level to provide the highest motor efficiency. With a small load torque, a substantial energy saving can be achieved. For example, at 4% motor load torque for a general-purpose motor, the motor efficiency under Optimum excitation control is about 30% higher than the motor efficiency under V/F control.Improved starting torqueAdvanced optimum excitation control, which has been newly developed, provides a large starting torque while maintaining the motor efficiency under the conventional Optimum excitation control. Without the need of troublesome adjustment of parameters (acceleration/deceleration time, torque boost, etc.), acceleration is done in a short time. Energy saving operation with the utmost improved motor efficiency is performed during constant-speed operation.Motor tuningThe offline auto tuning function to measure circuit constants of the motor enables optimal operation of motors even when motor constants vary, or when the wiring distance is long. Depending on the motor characteristics, sensorless operation can be performed for various manufacturers' general-purpose motors, permanent magnet (PM) motors. With the use of high-efficiency IPM motors, further energy savings are achieved when tuned with the FR-F800 inverter drive.More energy saving features- Regenerated power can be recovered when multiple inverters are connected to a power regeneration or the high power-factor converter through a common bus. The regenerated energy is used by another inverter, and if there is still an excess, it is returned to the power supply, saving on the energy consumption.- The inverter cooling fan can be controlled depending on the temperature of the inverter heatsink.- The energy saving effect can be checked using an operation panel, output terminal, or network. The output power measured by the inverter can be output in pulses, with cumulative power be easily checked.Find out more about the Mitsubishi FR-F800 inverter drive hereSee the new F800 at 999 Inverters
