Quincy Compressor QR-25 Series Instruction Manual page 33

Trouble
Excessive Vibration
(cont.)
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)
QR-25 Series
52201-107, December 2012
Probable Cause
•Foundation or frame inadequate
•Piping inadequately supported or tightened into a bind
•Excessive discharge pressure
•Compressor feet may need to be leveled with shims
•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 pump direction reversed
•Oil sump strainer plugged
•Excessive leakage at crankshaft seals
•Low oil level
•Oil pump incorrectly assembled to the bear ing carrier ("o"ring not
properly located between oil pump body & bearing carrier)
•Oil pressure adjusting screw not set properly
•Defective oil pressure gauge
•Plugged oil filter
•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 valve unloader
•Pilot valve or pressure switch set incor rectly or defective
•Pressure switch wired incorrectly
•Hydraulic valve or three way valve not functioning properly
•Tube to compressor unloader valve plugged
•Intercooler restricted or plugged
•Compressor valves in second stage broken or not functioning properly
•Pilot valve or pressure switch set incor rectly or defective
•Pressure gauge defective
33
Quincy Compressor
3501 Wismann Lane, Quincy IL - 62305-3116