Quincy Compressor QT Series Instruction Manual page 45

Trouble
Intercooler pressure
abnormally low
Compressor overheats
High discharge
temperature
Compressor knocks
QT/QTS Series
2022208700, September 2018
Probable Cause
•Compressor valves or head unloaders in first stage not functioning
properly or defective
•Restricted air inlet filter or suction line
•Pilot valve or pressure switch set incor rectly or defective
•Pressurized air at head unloader not vent ing properly when demand for
air is re quired
•Compressor valve or head gasket leaking
•Worn piston rings
•Leaking air at intercooler or intercooler connections
•Clogged intake system
•Defective compressor valves
•Pressure setting too high
•Clogged intercooler, internally or exter nally
•Inadequate ventilation, or recirculation of hot air
•Pulley/sheave rotation wrong
•Incorrect speed
•Lubrication inadequate
•Compressor incorrectly sized
•Compressor valve assemblies defective
•Discharge pressure too high
•Inadequate ventilation or hot air recirculat ing
•Cooling surfaces of compressor or inter cooler excessively dirty
•Ambient temperature too high
•Scored or excessively worn cylinder walls
•Head clearance insufficient
•Piston loose in cylinder bore, cylinder bore worn, piston or piston rings
worn
•Worn rods or main bearing
•Wrong pressure setting, discharge pressure excessive
•Crankcase lubrication inadequate
•Loose pulley/sheave
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Quincy Compressor