Quincy QSF Series Instruction Manual page 47

PROBABLE CAUSE
Compressor does not unload when there is no air demand
Incorrect unload pressure setting
Faulty blowdown valve
Faulty solenoid valve
Faulty differential pilot valve
Leaks in control lines
Leaks in service lines
Loose or broken wires
Compressor does not revert to load when service line pressure drops to reset pressure
Incorrect load pressure setting
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
Loose wiring connections
Leaks in control lines
Leaks in service lines
Excessive Water in Plant Air Distribution System
Incorrect operating temperatures
Clogged moisture separator/trap
Installation/Application
Faulty cooler-leaks
CORRECTIVE ACTION
Adjust to proper setting.
Repair or replace as necessary.
Repair or replace as necessary.
Repair or replace as necessary.
Check all control line fittings and tubing.
Check lines before MPC valve.
Check all wire terminals for tightness. Replace any broken or
pinched wires.
Adjust to proper setting.
Check and tighten wiring terminals.
Check and repair air inlet valve.
Repair or replace as necessary.
Check and replace timer.
Orifice plugged. Clean or replace as necessary.
Check and tighten wiring terminals.
Check and repair any leaks.
Check plant air distribution system for leaks.
Check thermal valve. Discharge temperature should be a minimum
of 170°F.
Clean or replace as required.
Check other compressors on same system.
Replace cooler.
Quincy Compressor – QSF Series
Section VII– Troubleshooting
43