How to connect a screw air compressor to a frequency converter

What is a frequency control rotary screw compressor?

Frequency control rotary screw compressors, typically saves users 20 to 35% on electricity when applied to variable loads. An inherent advantage of frequency converter equipped compressors is the ability to start and stop the compressor as often as needed.

What is a frequency converter used for?

Traditional frequency converter applications include fluid pumps, HVAC, conveyor systems, and positive-displacement rotary-lobe blowers. Only recently have they been applied to rotary-screw air compressors. Frequency control rotary screw compressors, typically saves users 20 to 35% on electricity when applied to variable loads.

How to choose a rotary screw compressor?

On the compressor side, the selection is ultimately based on a study of appropriate available technologies, as well as evaluation of existing equipment. In some instances, such as a continuous demand at full load, a fixed-speed rotary screw compressor may be the best solution.

Does a lower frequency affect a compressor's efficiency?

The permissible switching frequency, or ability to switch start/stop modes, drops off the higher the rating. But lower frequency does not correspond with the frequency needed to efficiently switch compressors on or off as dictated by narrower on-off switching differentials resulting from actual air demand.

How efficient is a variable speed compressor?

The efficiency of variable-speed compressors controlled by a frequency converter is not constant over the complete control range. Between 70 and 30% of full flow, or speed, efficiency is reduced from 94 to 86% for a 94-kW motor, for example.

Does a compressor make a chirping sound?

A standard compressor with a frequency converter has a lot of audible electrical noise. It makes a high-pitched "chirping" sound in the motor. But the sound is practically eliminated thanks to large motors, large air ends, low speeds, radial fans, and enclosed packaging.