Not for
Reproduction
19
Capacity Control Device
Step
Response
Start
Compressed air flows into unloader chamber (
A
) because solenoid valve for purge control
SV1 is opened at start-up. The pressure in chamber
(A
) rises soon to close unloader valve
(
A
) fully and accordingly it can reduce the load at start-up.
Load Operation
After starting, SV1 is closed after automatic unloaded operation, and the air volume
which is sent to chamber (
A
) increases and decreases according to the rise and drop
of the discharge air pressure and consequently the opening width of the unloader valve
is changed. Further, engine revolution (RPM) is changed by the pressure which PRS1
detects, and it steplessly controls the air volume in the range from 0 to 100%.
Suction Port
Closing Unload
Operation
When compressed air pressure exceeds the rated pressure with reduction of air
consumption, PRS1 detects the pressure and it reduces engine speed (rpm) in proportion
to the pressure rise, and it closes unloader valve at the same time. When compressor
air-end becomes vacuum during unload operation, vacuum noise is caused. To prevent
this noise, it opens vacuum relief valve by detection of secondary pressure of pressure
regulator. Thus high vacuum condition of compressor air-end is prevented.
Purge Control
Unload Opertion
When the certain set time (it can be changed.) has passed at lower pressure than the set
negative pressure, detecting the negative pressure inside the compressor air end with a
pressure sensor PRS2, solenoid valve SV1 opens and it closes unloader valve. At the same
time, it functions to relieve the compressed air from separator receiver tank to the atmosphere
and thus it lowers the pressure. Thus the compressor power is saved. When air consumption
increases, and the pressure used for load drops below the set pressure, pressure sensor
PRS3 detects it and it disengages the purge control (SV1 closes) to start full load operation.
Stop
When stopping operation, it opens Auto relief valve to relieve the compressed air in
separator receiver tank to atmosphere, detecting the pressure inside compressor air-end.
A
Summary of Contents for 185 CFM
Page 8: ...N o t f o r R e p r o d u c t i o n 8 ALLMAND COM L B C F A K G E D J H I N M ...
Page 35: ...N o t f o r R e p r o d u c t i o n 35 Data Adjustment Procedure ...
Page 37: ...N o t f o r R e p r o d u c t i o n 37 ...
Page 38: ...N o t f o r R e p r o d u c t i o n 38 ALLMAND COM ...
Page 39: ...N o t f o r R e p r o d u c t i o n 39 Wiring Diagram ...
Page 41: ...N o t f o r R e p r o d u c t i o n 41 Air Piping Compressor Oil Piping ...