Sullair 20/12 Series Operator's Manual And Parts List page 36

Section 6
MAINTENANCE
TROUBLESHOOTING (CONTINUED)
SYMPTOM
COMPRESSOR SHUTS DOWN
WITH AIR DEMAND PRESENT (cont.)
COMPRESSOR WILL NOT BUILD
UP FULL DISCHARGE PRESSURE
LINE PRESSURE RISES ABOVE
CUT- -OUT PRESSURE SETTING
ON PRESSURE SWITCH
32
PROBABLE CAUSE
Discharge Temperature Thermistor
Switch Open
Low Fluid Pressure
Air Demand is Too Great
Dirty Air Filter
Pilot Pressure Regulator Out
of Adjustment
Defective Pilot Pressure Regulator
Defective Minimum Pressure Valve
Inlet Valve Not Opening Completely
Defective Closed Inlet Solenoid
Valve
Defective Closed Inlet Solenoid
Valve Timer
Leak in Control System Causing
Loss of Pressure Signals
Defective Pressure Switch
Defective Pilot Valve
REMEDY
Defective blowdown valve; blowdown valve
should exhaust sump pressure to the
atmosphere when maximum operating
pressure is reached.
Cooling air flow restricted; clean cooler and
check for proper ventilation.
Ambient temperature is too high; provide
sufficient ventilation.
Low fluid level; add fluid.
Clogged filter; change the fluid filter element
and change the bearing filter element if main- -
tenance indicator shows red.
Thermal valve not functioning properly;
replace element.
Defective discharge temperature thermistor
switch; check for a short or open circuit to
probe and correct wiring, or also check for
short or open circuit to the control card. If
current is not present, replace the control
card. Should the above check out normal, it is
possible that the thermistor probe is defe- -
tive.
Clogged filter; clean main fluid filter element
or change bearing filter element.
Check service lines for leaks or open valves.
Check the filter indicator and change or clean
element if required.
Adjust regulator according to control
adjustment instructions in the Maintenance
section.
Check diaphragm and replace if necessary
(kit available).
Check that the piston is moving freely.
Check and readjust control linkage.
Broken spring in Sullicon Control.
Inlet cylinder not extended.
Repair or replace.
Replace.
Check for leaks.
Check that diaphragm and contacts are
functioning properly and are not damaged.
Repair or replace if necessary (kit available).
Check that Sullicon Control lever is moved to
a completely stroked position when the pres- -
sure switch contacts close. Repair or replace
if necessary (kit available).