Oil System - Atlas Copco GA55 Instruction Book

Instruction book
1.1.2 Oil system (Fig. 1.6)
In air receiver/oil separator (AR), most of the oil is removed
from the air/oil mixture centrifugally. The balance is removed
by oil separator element (OS). The oil collects in the lower
part of air receiver/oil separator (AR), which serves as oil tank.
The oil system is provided with a by-pass valve (BV). When
the oil temperature is below 40 degrees celsius 1), by-pass valve
(BV) shuts off the oil supply from oil cooler (Co). Air pressure
forces the oil from air receiver/oil separator (AR) through oil
filters (OF) and oil stop valve (Vs) to compressor element (E)
and its lubrication points. Oil cooler (Co) is by-passed.
OF
SV
UA
AR
CV
AR Air receiver
Co Oil cooler
CV Check valve
E Compressor element
FN Fan
2920 1381 02
FN M2 Co VP
Vs E
MTa Condensate trap
M1 Drive motor
M2 Fan motor
OF Oil filters
SV Safety valve
UA Unloader
Fig. 1.3 Front view of GA90C
By-pass valve (BV) starts opening the oil supply from cooler
(Co) when the oil temperature has increased to the above-
mentioned value. At approx. 55 degrees celsius 1) all the oil
flows through the oil cooler.
Oil stop valve (Vs) prevents the compressor element from
flooding with oil when the compressor is stopped. The valve
is opened by element outlet pressure when the compressor is
started.
1 MTa
2 M1
VP
Vs
1
2
50511F
Vent plug
Oil stop valve
Electric cabinet
Arrow, motor rotation direction
(depends on compressor type)
5