Atlas Copco GA 160 VSD, Instruction Book

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Rear view of air-cooled GA
Air flow
Air drawn through filter (AF) is compressed in compressor element (E). Compressed air and oil are discharged
through check valve (CV) to air receiver/oil separator (AR) where oil is separated from the compressed air.
The air is blown through minimum pressure valve (Vp) to air cooler (Ca).
On GA Pack compressors, the cooled air is discharged through condensate trap (MTa) and outlet (AOw)
towards the air net.
Check valve (CV) prevents blow-back of compressed air.
Minimum pressure valve (Vp) prevents the receiver pressure from dropping below a minimum pressure. The
valve has a built-in check valve.
Oil system
Air pressure forces the oil from receiver (AR) through oil cooler (Co), filters (OF), oil stop valve (Vs) and an
oil injection valve to the compressor element (E) and the lubrication points. The oil injection valve will open
at higher ambient temperatures to keep the element outlet temperature low.
A by-pass valve by-passes the oil cooler (Co) when the injection pressure is low, to ensure a sufficient initial
oil flow to the element when starting the compressor or when switching from unload to load.
For air-cooled units, the oil temperature is controlled by regulating the speed of the fans (FN), to avoid
overcooling and consequently condensation in the air receiver (AR).
Instruction book
APF192090 15