Question

A large refrigeration plant has three compressors with synchronous motor drives and seven compressor with squirrel cafe induction motors. One important reason for this arrangement is

A) provide some refrigeration capacity in the event of an AC power failure.
B) allow some variation in capacity, since synchronous motors can easily be run at various speeds.
C) correct the overall power factor.
D) stabilize the overall plant demand factor.

Answer 1

The presence of both synchronous and induction motors in a refrigeration plant is primarily to correct the overall power factor, enhancing operational efficiency and reducing power losses.

Step-by-step explanation:

The question concerns the arrangement of compressors in a large refrigeration plant where there are three compressors with synchronous motor drives and seven compressors with squirrel cage induction motors. One important reason for using a combination of synchronous motors and induction motors in a refrigeration plant is to correct the overall power factor of the plant. Synchronous motors can be over-excited to provide leading power factor, which compensates for the lagging power factor typically exhibited by induction motors and other inductive loads. This correction helps in reducing power losses and improving the efficiency of electrical power utilization throughout the plant.