5
2920 1190 05
Instruction book
Industrial Air Division
1.1.2 Oil system (Figs. 2)
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 60°C (140°F), 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 filter(s)
(OF) and oil stop valve (Vs) to compressor element (E) and its
lubrication points. Oil cooler (Co) is by-passed.
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. 75°C (167°F) all the oil flows
through the oil cooler.
1.1.3 Cooling and condensate drain systems
(Figs. 3 and 4)
The cooling system comprises air cooler (Ca) and oil cooler
(Co). GA50 VSD and GA90 VSD are air-cooled compressors,
the cooling air is generated by fan (FN). GA50 W VSD and
GA90 W VSD are water-cooled compressors.
A moisture trap (MT) is provided in the air outlet system. The
trap is equipped with a valve for automatic condensate draining
during operation (Da-Fig. 5) and a manually operated valve
for draining after stopping the compressor (Dm-Fig. 5).
1.2 Regulating system
If the air consumption is less than the air output of the
compressor, the net pressure increases. When the net pressure
differs from the setpoint (desired net pressure), the regulator
will decrease the motor speed. If the net pressure keeps on
rising when the motor runs at minimum speed, the regulator
will stop the motor. If the motor is stopped automatically and
the net pressure approaches the setpoint, the regulator will
restart the motor.
1.3 Electrical system
The system comprises (Figs. 6):
1. Compressor motor (M1) and fan motor (M2)
2. Elektronikon control module (Fig. 7a)
3. Compressor start button (I) and stop button (O)
4. Isolator switch (S0)
5. Electric cabinet (Figs. 8)
6. Sensors for the compressor element outlet temperature
(TT11), for the pressure difference over the oil separator
(PDT1) and for the air outlet pressure (PT20). Water-cooled
compressors are also provided with a sensor for the cooling
water outlet temperature (TT51).
1.4 Elektronikon control module
The control module consists of an Elektronikon regulator and
a control panel.
AF.
Air filter
AR.
Air receiver/oil separator
AV.
Air outlet valve
BV.
Oil cooler by-pass valve
Ca.
Air cooler
Co.
Oil cooler
CV.
Check valve
CV1.
Check valve
Da.
Automatic condensate drain,
air cooler moisture trap
Dm.
Manual condensate drain, air
cooler moisture trap
DP1.
Oil drain plug, air receiver
DP2.
Oil drain plug, oil stop valve
DP3.
Oil drain plug, compressor
element
E.
Compressor element
E1.
Elektronikon control module
FC.
Oil filler plug
FN2.
Fan, compressor coolers
Gl.
Oil level gauge
MT.
Air cooler moisture trap
M1.
Compressor motor
M2.
Fan motor, compressor coolers
OF.
Oil filter
OS.
Oil separator element
PDT1. Differential pressure sensor, oil
separator
PT20.
Pressure sensor, air outlet
Rf1.
Nozzle, only for GA50 VSD
Rf2.
Restrictor
SV.
Safety valve
TT11.
Temperature sensor, compres-
sor element outlet
Vp.
Minimum pressure valve
Vs.
Oil stop valve
Y1.
Solenoid valve, blow off
1.
Oil scavenging line
2.
Blow-off air flexible
Figs. 2. Flow diagrams
