Traditional compressor (Star/Delta starting system)

First the motor is started in Star connection where the starting current is about 2,5 times the nominal current. (The motor torque is only 1/3 of nominal torque and this will stress the motor). By switching over to Delta, another current spike appears that is about 4 times nominal motor current. Following, this current is brought back to a nominal level in order for the motor to run at full load.

Variable speed controlled compressor (Inverter)

In this type of regulation no current spikes are generated because the inverter transforms the constant voltage & frequency into a variable Voltage/frequency system and no switching over current spikes are generated increasing the lifetime of the system. Variable speed compressors speed up and slow down so as to match air supply with air demand ensuring energy savings.

Conclusively, the variable speed controlled system – inverter ensures:

• Energy savings up to 40%.
• Smooth motor starting.
• Continuous speed variation to achieve the exact required air volume.
• Constant network pressure (± 0,1 bar).
• User controlled selection of the network pressure (variable adjustment between 5 and 13 bar).
• No expensive and long unload times (energy efficient).
• No Load/Unload switching to ensure less stress to the machine