Quincy QPNC Series Parts And Instruction Manual page 15

Table 3 — Troubleshooting Guide, continued
Symptoms
D. Motor cuts out on overload.
E. The motor hums and does not
start.
F. The machine (compressor) has
stopped and does not restart
even after a few minutes.
G. The compressor is very noisy.
Cause
1. The dryer is working outside its
rating.
2. The dryer is working under bad
conditions for air-cooled
condenser.
3. The cooling circuit is not
working with the right
refrigerant charge.
1. The line voltage is too low.
2. The machine was switched off
and on again without leaving
enough time for pressure
balancing.
3. The starting system of the motor
is defective.
1. The overload protection has
intervened: see B2, B3 and C3
above.
2. The compressor motor has
burned out.
1. Trouble with the internal
mechanical parts or with the
valves.
Back to TOC
Remedy
1a. Check the flow rate of treated air.
1b. Check the room temperature.
1c. Check the air temperature at the dryer
inlet.
2a. Clean the condenser.
*2b. Check the operation and the
calibration of the fan cycling press.
Switch.
*2c. Check the operation of the fan.
*3a. Check if there are leaks of
refrigerating gas.
*3b. Charge it again.
1a. Contact the electric power company.
2a. Wait a few minutes before starting the
machine again.
*3a. Check the running and starting relays
and condensers (if installed).
1a. See remedies above.
2a. Replace.
1a. Repair or replace.
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