A compressor drive motor is an asynchronous motor that must cope with a variable, high starting-torque demand during the air or gas compression cycle, which is why its rotor strength and thermal capacity have to be specified carefully. DRG Motor builds electric motors sized for the demanding load profile of screw and piston compressors.

What a Compressor Load Asks of the Motor

Piston compressors draw a pulsating torque that changes with each revolution, so they need high breakaway torque and a robust bearing arrangement. Screw compressors load more smoothly, but heat dominates during long continuous running. In both cases the motor must be chosen with a housing that dissipates heat and the correct insulation class.

Insulation, Protection and Continuity

Compressor rooms are dusty, humid and hot. IP55 protection guards against dust and splashing water, while Class F insulation leaves a safety margin against high winding temperature. The S1 continuous duty rating defines a thermal design suited to the compressor's uninterrupted daily output.

Speed Selection and Efficiency

Most screw compressors run on a 1500 rpm (4-pole) or 3000 rpm (2-pole) motor; the gear ratio and air delivery decide the choice. IE3 Premium and IE4 Super Premium motors noticeably cut the electricity consumption of a compressor that runs all day.

Specifying the Right Motor for Your Compressor

DRG Motor offers cast iron compressor motors from 0.55 to 355 kW with B3 foot and B5 flange mounting. Tell us the compressor type, air delivery and duty cycle, and we will select the right power, speed and efficiency class together.