Sullair LS-120 series Operators Manual And Parts Lists page 46

Section 8
TROUBLESHOOTING- ELECTRO-MECHANICAL
8.2 TROUBLESHOOTING GUIDE-STANDARD ELECTRO-MECHANICAL (CONTINUED)
SYMPTOM
COMPRESSOR SHUTS DOWN
WITH AIR DEMAND PRESENT
(CONTINUED)
COMPRESSOR WILL NOT
BUILD FULL DISCHARGE PRES-
SURE
LINE PRESSURE RISES ABOVE
CUT-OUT PRESSURE SETTING
ON PRESSURE SWITCH
40
PROBABLE CAUSE
Discharge Temperature Switch Open
(Continued)
Air Demand is Too Great
Dirty Air Filter
Pressure Regulator Out of
Adjustment
Defective Pressure Regulator
Leak in Control System Causing
Loss of Pressure Signals
Defective Pressure Switch
Defective Regulator Valve
Plugged Control Line Strainer
REMEDY
Cooling water flow insufficient; check water
lines and valves (water-cooled only).
Cooler plugged; clean tubes. If plugging per-
sists, install water conditioner (water-cooled
only).
Cooling air flow restricted; clean cooler and
check for proper ventilation.
Ambient temperature is too high; provide suf-
ficient 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.
Water flow regulating valve not functioning
properly; change (water-cooled only).
Defective discharge temperature switch;
check for a short or open circuit to probe and
correct wiring.
Check service lines for leaks or open valves
up.
Check the filter indicator and inspect and/or
change element if required.
Adjust regulator according to control adjust-
ment instructions in the Maintenance section.
Check diaphragm and replace if necessary
(kit availble).
Check for leaks.
Check that diaphragm and contacts are not
damaged. Replace if necessary.
Check that air bleeds from control orifice
when the pressure switch contacts open.
Readjust; Repair or replace it if necessary (kit
available).
Clean strainer (screen and o-ring replace-
ment kit available).