Sullair LS-100L Operator's Manual page 34

Section 5
OPERATION- ELECTRO-MECHANICAL
5.2 PURPOSE OF CONTROLS-STANDARD ELECTRO-MECHANICAL (CONTINUED)
CONTROL OR INDICATOR
AUTO LED
FLUID LEVEL SIGHT GLASS
SEPARATOR RETURN LINE SIGHT
GLASS
THERMAL VALVE
MINIMUM PRESSURE/CHECK VALVE
COMPRESSOR DISCHARGE
TEMPERATURE SWITCH
WATER PRESSURE SWITCH
(water-cooled compressors only)
PRESSURE RELIEF VALVE
MODULATING INLET VALVE
PRESSURE REGULATOR
SOLENOID VALVE
PRESSURE SWITCH
BLOWDOWN VALVE
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PURPOSE
Indicates when compressor is in auto mode.
Monitors fluid level in the sump. The fluid must be visible in the
glass. Check the level when the compressor is shut down.
Maximum fill level is the level of the fill port, minimizing the risk
of overfilling.
Used to indicate fluid flow in the return line. When the compres-
sor is running at full load, fluid flow should be visible in this sight
glass. There may be little or no flow when the compressor is
running unloaded, but a sluggish flow at full load indicates a
need to clean the return line strainer.
Regulates flow of fluid to and around the cooler. It is designed to
maintain a minimum operating temperature of 180ºF (82ºC); use
for fast warm-up on start-up.
Maintains minimum of 55 psig (3.8 bar) in the compressor sump.
Valve piston restricts receiver air discharge from receiver/sump
when pressure falls to 55 psig (3.8 bar). Also prevents backflow
into the sump during unload conditions and after shutdown.
Designed to shut the compressor down when the
discharge temperature reaches 235ºF (113ºC).
It prevents operation when water pressure of compressor is
inadequate.
Opens sump pressure to the atmosphere should pressure inside
the sump become too high. Operation of this valve indicates that
the high pressure switch is either faulty or out of adjustment.
Regulates the amount of air allowed to enter the air compressor.
This regulation is determined by the amount of air being used at
the service line. Also acts as a check valve to prevent reverse
compressor rotation at shut down.
Allows a pressure signal to reach the air inlet valve to control air
delivery according to demand.
Bypasses the pressure regulator valve causing the inlet valve to
close when the compressor reaches maximum operating pres-
sure. Also activates blow-down valve.
Senses service line pressure. When line pressure reaches maxi-
mum setting the pressure switch signals the pilot valves to
unload the compressor.
Vents sump pressure to the atmosphere during unload condi-
tions and shutdown.