Sullair LS-20 Operator's Manual And Parts List page 29

6.1 INTRODUCTION
While Sullair has built into the 20 Series package a
comprehensive array of controls and indicators to
assure its proper operation, the user should recog-
nize and interpret readings which call for service or
indicate the onset of a malfunction. Before starting
the unit, the user should become familiar with the
controls and indicators -- their purpose, location,
CONTROL OR INDICATOR
EMERGENCY STOP SWITCH
THERMAL O/L RESET
INLET POPPET VALVE
SPIRAL VALVE (OPTIONAL)
PRESSURE REGULATOR (INLET POPPET
VALVE)
PRESSURE REGULATOR (WITH OPTIONAL
SPIRAL VALVE)
SOLENOID VALVE
MINIMUM PRESSURE VALVE
PRESSURE RELIEF VALVE
BLOWDOWN VALVE ASSEMBLY
COMPRESSOR OPERATION
and use.
6.2 PURPOSE OF CONTROLS
All Supervisor II module (Supervisor) related func-
t ions and indic at or s ar e pr es ent ed in
please refer to that section for your information.
Additional indicators and functions included in the
package are as follows:
PURPOSE
Pushing in this switch, found adjacent to the Supervisor
II, cuts all AC outputs from the latter and de--energizes
the starter. A fault message (E STOP) is displayed by
the Supervisor II until the button is pulled out and the "O"
pad is depressed.
Momentarily pushing this button, found on the starter's
thermal overload element housing, re--closes the lat-
ter's contacts after a current overload takes place.
Please be aware that the elements must be allowed to
cool sufficiently before resetting.
Throttles the air flow to the compressor inlet in order to
match air supply to the demand. Also prevents air/fluid
backflow through compressor inlet during shutdown.
Internally bypasses and controls the air flow capacity
of the compressor, in order to match air supply to the
demand. This device is optional.
Opens a pressure line between the sump and the inlet
poppet valve, allowing it to regulate air delivery accord--
ing to the air demand.
Opens a pressure line between the service line and
the spiral valve actuator allowing the spiral valve to
regulate air delivery according to air demand.
Electrically actuated, 3--way valve which controls the
flow of pneumatic logic signals. Used throughout pack-
age to:
SOpen the blowdown valve.
SClose the inlet poppet valve during shutdown opera--
tion.
SClose the spiral valve during shutdown operation.
Maintains 50 psig (3.5 bar) pressure in sump vessel.
When pressure falls below 40 psig (2.8 bar), it closes
and isolates the sump vessel from the air service line,
thus preventing compressed air backflow during un-
loading or shutdown.
Vents the sump vessel to atmosphere if the com-
pressed air pressure exceeds 200 psig (13.8 bar). Its
operation indicates fault with the Supervisor II opera-
tion or its programming.
Vents the sump vessel to atmosphere during unload-
ing and shutdown.
Section 6
S ec t ion 4. 2, s o
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