The principle of rotary screw air compression is really no different than reciprocating (piston) compression. Both are positive displacement machines that take in a fixed volume of air at atmospheric press.
[pdf] If your compressor is experiencing loading or unloading issues, check the electrical components, such as the solenoid valves, and inspect mechanical components like the air filter, intake valve, and pressure switch.
[pdf] Checkout Current Transformers (CTs) and check resistance across each one while it is disconnected. All resistances should be within 10% of one another. Also do a diode test on the CT inputs on each compressor module. (The diode test is described in RTAA-SVB10B-EN.)
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