Sullair LS20 Operator's Manual And Parts List page 52

Section 9
TROUBLESHOOTING- ELECTRO-MECHANICAL
9.2 TROUBLESHOOTING GUIDE- ELECTRO-MECHANICAL (CONTINUED)
SYMPTOM
COMPRESSOR SHUTS DOWN
WITH AIR DEMAND PRESENT
(CONT.)
COMPRESSOR WILL NOT
BUILD FULL DISCHARGE
PRESSURE
LINE PRESSURE RISES
ABOVE CUT-OUT PRESSURE
SETTING ON PRESSURE
SWITCH
46
PROBABLE CAUSE
Discharge Temperature Switch Open
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
REMEDY
Cooling water temperature too high; increase
water flow (water-cooled only).
Cooling water flow insufficient; check water
lines and valves (water-cooled only).
Cooler plugged; clean tubes. If plugging
persists, 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 sec-
tion.
Check diaphragm and replace if necessary
(kit available).
Check for leaks.
Check that diaphragm and contacts are not
damaged. Replace if necessary. Check that
air bleeds from control orifice when the pres-
sure switch contacts open.
Readjust; Repair or replace it if necessary
(kit available).