Section 4
COMPRESSOR SYSTEMS
16
The pressure regulator has an orifice which vents a
small amount of air to the atmosphere when the
pressure regulator controls the inlet control valve.
The orifice also bleeds any accumulated moisture
from the pressure regulator.
UNLOAD MODE - IN EXCESS OF 110 PSI G (7.6
bar)
When a relatively small amount or no air is being
used, the service line pressure continues to rise.
When it exceeds 110 psig (7.6 bar), the Supervisor
Control System de-energizes the solenoid valve al-
lowing sump air pressure to be supplied directly to
close the inlet valve. Simultaneously, the solenoid
valve sends a pneumatic signal to the blowdown
valve. The blowdown valve opens the sump to the
atmosphere, reducing the sump pressure to approx-
imately 20 to 30 psig (1.4 to 2.1 bar). The check
valve in the air service line prevents line pressure
from returning to the sump.
When the line pressure drops to the low setting (cut-
in pressure; usually 100 psig [6.9 bar] on low pres-
sure [“L”] compressors and 125 psig [8.6 bar] on
high pressure [“HH”] compressors, 175 psig [12.1
bar] on [“XH”] compressors), Supervisor energizes
the solenoid valve and allows the blowdown valve to
close. The re-energized solenoid valve again pre-
vents line pressure from reaching the inlet control
valve. Should the pressure begin to rise, the pres-
sure regulator will resume its normal function as pre-
viously described.
AUTOMATIC OPERATION
For applications with varied periods of time when
there are no air requirements, Supervisor’s AUTO-
MATIC mode allows the compressor to shutdown
(time delayed) when no compressed air require-
ment is present and restart as compressed air is
needed.
To Next Page
Loading...
