PM VSD Screw Air Compressors

Air demand in a workshop is rarely constant: low on the early shift, higher at full load, dropping again at night. A fixed-speed machine adjusts by loading and unloading, so when demand is low the motor still runs at full speed and the extra air is blown off. PM VSD varies speed continuously with demand, producing only as much as is used. Under this direction, the firstAir brand offers six series covering 7.5–300 kW.

What PM VSD Brings

All six series are rated for PM VSD starting. Compared with loading and unloading, continuous speed control keeps pipe network pressure fluctuation smaller and downstream equipment steadier; VSD soft starting also reduces the impact of starting current on the grid and the machinery. The more pronounced the fluctuation in demand, the more this control method pays off.

Selecting by Power Range

• Low power (7.5–37 kW): FASM (0.33–6.70 m³/min), FAS (0.33–6.70 m³/min) and FASV+-MA (0.42–6.55 m³/min), suited to a single point or a small workshop;
• Medium power (7.5–75 kW): FPM, with air delivery of 0.33–13.80 m³/min, covering medium production lines;
• High power (45–300 kW): FASV-M and FASV, with air delivery of 2.52–55.00 m³/min, aimed at centralized supply and high-flow duty.

Technical Specifications

Selection Points

1. First determine the usual working pressure, then match the air delivery at that pressure; pressure and air volume trade off against each other;
2. Give priority to PM VSD in shops with large demand fluctuation, and evaluate comprehensively where demand is constant and full over the long term;
3. For high-power centralized supply, you can further compare two-stage models;
4. The low-power FASV+-MA has a voltage / frequency of 220/380 V, 60 Hz, so check that it matches the site specification when selecting.