These devices are used in refrigeration equipment. The motors driving these applications usually run at a constant speed, even though the load is varying. Using variable speed drives (VSDs), the speed of the motor can be slowed down, thereby reducing the amount of energy consumed. A VSD can be retrofitted to most existing systems.
The mechanical controls are simply locked fully open and the VSD directly controls the speed of the electric motor. Since cold storages and fridge plants typically run for 24 hours, most refrigeration drive applications are potential VSD candidates. Any refrigeration system with a wide variation in operating hours or with a heat load that is less than the peak load can benefit from a VSD. ABB applied existing technology to the food industry by developing bolt on variable speed drive motors for refrigerators.
These keep units running at regular speeds and prevent peaks of energy use when something is put inside a fridge, reducing energy use and costs and cutting carbon footprints. This increases the life of the equipment. Instead of continually running at full speed, the lower speed reduces stresses, increases the equipment life and extends service intervals, cutting maintenance costs.