VFD drives are known as Variable Frequency Drives. VFD drives are also known as variable speed drives (VSDs), adjustable speed drives, motor speed controllers and inverters. VFD drivesare solid state controllers used in AC or DC electric motor applications. Most VFD drives are applied on alternating current (AC) electric motors in the industrial manufacturing world. There are some direct current (DC) electric motor applications that apply variable frequency drives, but most manufacturers seek AC motors because DC motors are expensive and they’re more prone to failure. VFD drives can also be used as a phase converters when three phase motors need to be operated from single phase power.
VFDdrives areused in mills, lathes, fans, air compressors, pumps, conveyors, welders, robots and many other electric motor applications to control the speed regulation of an electric motor. Over 30 percent of the world’s electrical energy is consumed by electric motors in fixed-speed fan, pump, and air compressor applications. The basic idea for using a VFD on mills, air compressors, and fans is to decreasethe amount of electrical energy being consumed toreduce electricity costs.
Only about3% of the total installed AC electric motors in the United States use VFDdrives.An estimated 60-65% of electrical energy in the United States is used to supply electric motors, and 75% of that electrical energy is consumed by fan, pump and air compressor applications.Approximately 18% of the electrical energy used in the 40 million motors in the United States could save power consumption via efficient energy improvement by using VFD drives on these electric motor applications.
Performance and Operation
VFDdrives are applied to alternating current (AC) electric motors to increase quality control and reduce energy consumption during the process of manufacturing.VFD drives increase quality control by monitoring the electric motor speed, pressure, temperature, torque, and tension; and then adjusting the motor to operate as economical as possible to meet the VFDcriteria.
Fixed-speed electric motor loads exposethe electric motor to high starting torque and electrical current surges that are up to eight times the full-load motor current. When VFDdrives are used on an electric motor, the VFDgradually ramps the electric motor up to full load operating speed; this decreases mechanical and electrical stress, which minimizes motor maintenance and motor repair costs which extends the life of the electric motor and manufacturing equipment.VFD drives haveunique programming capabilities that allow for application specific patterns to minimize electrical and mechanical stress on electric motors during operation. Every VFD drive manufacturer uses a unique parameter selection designed so that every manufacturing field has VFD products designed for their industry.
Repair and Replacement
VFD repair should be taken with extreme caution. VFD repair should only be performed by technicians who have required training and experience to work with electrical equipment. Precision Electric strongly recommends to consult an expert in the field when repairing VFD equipment.Many VFD controllers have an internal DC bus that retains a charge after power has been cut to the drive, as a result, it does not mean it’s safe to work with. Technicians working with VFD repair must always take extra precautions to ensure proper safety measures are taken, or injury or even death may occur.
Precision Electric offers free repair quotes and offers 24 hour emergency repair services. Repair services performed by Precision Electric include anin-service 12 month warranty; the Precision Electric in-service warranty begins the day repaired work is installed and put into service.