Quincy Compressor Industrial Series Instruction Manual page 38

Trouble
Excessive drive belt wear
Low oil pressure
Compressor loads
and unloads excessively
Defective pressure switch •Moisture &/or oil buildup on the pressure switch diaphragm
Excessive air pressure
in air receiver
Excessive
intercooler pressure
(Two stage models only)
Industrial / Air Master Series
50161-105, March 2008
Probable Cause
•Pulley/sheave out of alignment
•Belt too loose or too tight
•Belt slipping
•Pulley/sheave wobbling
•Pulley/sheave groove damaged or rough
•Incorrect belts
•Oil sump strainer plugged
•Excessive leakage at crankshaft seals
•Low oil level
•Oil pump incorrectly assembled to the bearing carrier ("o"ring not
properly located between oil pump body & bearing carrier)
•Oil pressure adjusting screw not set properly
•Defective oil pressure gauge
•Air receiver too small
•Compressor valves or unloaders defective
•Excessive system leakage
•Compressor operating at incorrect speed
•Unloader pilot differential set too close
•Pressure switch defective
•Ruptured diaphragm
•Burned contact points
•Plugged air passage from the receiver to the pressure switch
•Loose electrical connection
•Air pressure gauge inaccurate
•Leaks in unloader piping system
•Defective compressor head unloader
•Pilot valve or pressure switch set incorrectly or defective
•Pressure switch wired incorrectly
•Tube to compressor head unloader plugged
•Intercooler restricted or plugged
•Compressor valves in second stage broken or not functioning properly
•Pilot valve or pressure switch set incorrectly or defective
•Pressure gauge defective
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Quincy Compressor
3501 Wismann Lane, Quincy Ill. - 62305-3116