AC Servo Motor Industrial Yaskawa Electric AC Servo Motor 850W SGMG-09A2RCS

Non-Regenerative AC Drives

In non-regenerative drives, commonly used with geared applications, overhauling energy is dissipated in the machine room through dynamic braking resistors. The amount of heat dissipated in the machine room is dependant on car speed, hoist motor horsepower, total car travel and duty factor. As any of the these factors increase, the amount of heat to be dissipated increases. In general, if hoist motor horsepower increases above 30HP, and the elevator travel is over 100 feet, special considerations are required when sizing dynamic braking resistors. The question of how to remove this heat energy from the machine room must also be addressed.

Regenerative AC Drives

The ultimate solution to disbursing heat energy typically produced by a nonregenerative drive is to specify a regenerative VFAC drive. While relatively new to the elevator industry, these drives are quite suitable for gearless AC applications. Unfortunately, these drives presently cost more than twice what a comparable nonregenerative drive would cost.