Sullair 375 - 4 - General; General; Purpose of Controls; Control or Indicator Purpose

29
375 Caterpillar Standard and Aftercooled/Filtered Operator’s Manual and Parts List
Section 4
GENERAL
GENERAL4.1
While Sullair has built into this compressor a complete set
of controls and indicators that allow the operator to control
and monitor the compressor’s operation and performance.
Operators should learn to recognize indications which
identify a service requirement or conditions that could lead
to (or show) a (current) malfunction. Before starting the
compressor, read this section thoroughly to gain familiarity
with the controls and indicators – their function and
location.
PURPOSE OF CONTROLS4.2
Control or Indicator Purpose
Engine Switch
Press this switch to the ON (ignition) position to energize
the electrical system of the compressor. Press the switch
to the START position to momentarily engage the starter
and start the compressor. Press the switch to the OFF
position to shut the compressor down. This switch is
located on the instrument panel.
Cold Weather Starting Aid Button
Push this button, prior to compressor start-up, to allow the
engine to pre-heat for easier starting.
Hourmeter
Indicates the accumulated hours of operation. Useful for
planning and logging service schedules.
Air Pressure Gauge
Continuously monitors the pressure inside the receiver
sump at various load and unload conditions.
Fluid Sight Level Glass
Indicates the uid level in the sump. Proper level is marked
halfway up the sight glass. Check the level when the
compressor is shutdown and on level ground.
Compressor Discharge Temperature Switch
Opens the electrical circuit to shut down the compressor
when the discharge temperature reaches a specic value
(See Specifications on page 25 and on page 27).
Thermal Valve
Functions as a temperature regulator by directing the
compressor uid either to the cooler or to the compressor unit.
Minimum Pressure Device
Maintains the minimum of 80 psig (5.6 bar) in the
compressor sump.
Pressure Relief Valve
Vents sump pressure to the atmosphere if pressure inside
the sump exceeds 250 psig (17.3 bar).
Air Inlet Valve
Regulates the amount of air allowed to enter the air
compressor inlet. Regulation is determined by a signal
from the pressure regulator(s).
Pressure Regulator(s)
Allows the pressure signal to reach the engine speed
control and the air inlet valve to control air delivery
according to demand.
Discharge Air Filter Differential Pressure Gauge
(Optional Aftercooled and Filtered Models Only)
Monitors the air lter (rst and second stage) condition. A
reading over 10 psig (0.7 bar) in the red zone indicates the
air lters require servicing.
Shutdown System/Annunciator Module (SSAM)
Monitors the compressor safety system for conditions
requiring shutdown. The annunciator on the instrument
control will ash the applicable shutdown code.