Quincy Compressor QSI Series Instruction Manual page 121

Probable Causes:
Compressor Does Not Revert To Load When Service Line Pressure Drops To Reset Pressure:
Faulty air pressure switch
Loose wiring connection
Jammed air inlet valve assembly
Faulty solenoid
Faulty timer
Faulty differential pilot valve
Compressor Will Not Time-out Or Shut Down When Unloaded (Auto/Dual Only):
Faulty timer
Leaks in control lines
Leaks in service lines
Faulty air pressure switch
Faulty air pressure sensors
Excessive Water in Plant Air Distribution System:
Clogged moisture separator/trap
Installation/Application
Faulty cooler/leaks
Corrective Action:
Adjust differential pressure regulator to
obtain desired modulation range.
Readjust air pressure switch so that the com-
pressor unloads at the desired pressure.
Correct in accordance with the instruction in
"Inlet valve not opening or closing in relation
to air demand" section of this troubleshooting
guide.
Replace with new air/fluid separator.
Check gauge for accuracy and replace if nec-
essary. Adjust control settings.
Check pressure relief valve for correct pres-
sure setting. If valve is still leaking, replace
it.
Drain water as needed to reduce water con-
tent in fluid below 200 PPM.
Check operation of thermostatic valve or wa-
ter regulating valve. If condition continues,
consult Quincy service department.
Quincy Compressor-QSI
®
Section IX - Troubleshooting
119