Important thing in this compressor is the condencer. It's used in commercial fridges. I bought new one without the fan.
Condencer is installed before the receiver. What this unit gives us? - Cooling of the air flow after it's heating when passing through the motor-compressor. Big temperature difference between hot air and cooled pipes creates condensation of water contained in the air flow.
In this system air flow goes to the upper pipe of the condencer than passes through its passages and goes out to the lower pipe where filter is installed. Condenced water flows down to the filter. The filter traps condenced water. After that air goes to the receiver.
I opened water drain valve many times but there was no water. So we can assume that this unit works and worth to be taken into account when building your own compressor.
At the out of the receiver another filter is installed. It provides last step filtration of the air passed through all the system. This air we receive at our airbrush.
Motor-compressors are cooled by fans that look like computer's coolers but they are not. Because they consume 220V.
All electric consumers can be swiched off separately. Everything has it's own switch and fuse.
Coolers and condencer's fan can work constantly, automatically swithed with starting/stopping of the compressors or switched off.
Pressostat is adjusted to 7,5 bar - switch off and 4 bar - switch on. Pressostat is used for regular home water pump.
I think I've said all I wanted to. If the information is useful for you I'm glad. Feel free to ask questions.