Thermal Overload Relays Tripping; Low Air Delivery; Low Receiver Pressure - Quincy Compressor QMA Series Instruction Manual

THERMAL OVERLOAD RELAYS TRIPPING
I
PROBABLE CAUSE
I
CORRECTION
1
kIi~h ambient condition will cause HAT shutdown.
]
Cod the
room and restart.
I
Excessive Discharge Pressure.
Lower M load pressure setting at differential pilot
valve. Lower air Dressure switch settinz.
Low voltage.
Check voltage & amperages while operating the unit at
full load and M pressure.
Loose overload connection.
Tighten mounting screws on thermal overload.
Incorrect thermal overload relay setting. Check motor name plate and compare to overload relay
setting.
Loose motor or starter wiring.
Check all connections for tightness.
Faulty motor.
Remove motor and have tested at authorized motor
manufacturer repair center.
I
LOW AIR DELIVERY
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PROBABLE CAUSE
I
CORRECTION
I
lPlu~~ed air intake filter element.
IClean air filter element or replace with new element. I
Excessive leaks in the service lines.
Check service lines for leaks with soapy solution.
Inlet valve not opening fully. Correct the situation in accordance with the instructions
in "Inlet Valve Not Closing in Relation To Air
I
lDemand" section of this trouble shooting guide.
LOW RECEIVER PRESSURE
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PROBABLE CAUSE
I
CORRECTION
I
Excessive air demand
Reevaluate air demand. Add additional compressors as
needed.
Excessive leaks in service lines.
Check service lines for leaks by testing with soap
solution.
Inlet valve not opening fully.
Correct the situation in accordance with the instructions
in "Inlet Valve not Opening or Closing in Relation to
Air Demand" section of this trouble shooting guide.
Plugged air intake filter. Clean air filter element or replace with new element,
Differential pilot valve not set correctly.
Readjust differential pilot valve to achieve desired
modulation range.
lAir pressure svvitch not set correctly.
\Readjustthe air pressure switch to the desiredcut-in
and cut-out pressure.
Faulty reservoir pressure gauge.
Check and if faulty, replace.
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