Horlick BVL Model motor-generator sets consist of a 4-pole, 1800 RPM, induction motor and a 4-pole, 1800 RPM, synchronous generator mounted on a rigid steel base and connected via a flexible coupling. The motor speed is controlled by a variable frequency drive. In standard applications, the motor speed can be adjusted from 1350-1950 RPM creating an output frequency on the generator that varies from 45-65 Hz.