Quantech QTC40160, Установка, эксплуатация и обслуживание

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Section 9 - Maintenance
Quantech
177
Form QTC4-NM2
Issue date: 05/12/2023
9
Table 35 - Troubleshooting guide, cont'd
Problem Possible cause Action
System fault:
high discharge pressure
Coils dirty Check and clean coils
Coils are damaged Comb out fins
Fans not operating
Check fan fuses
Check fan rotation
Check fan motor/blade
System is overcharged Remove charge and check subcooling
System fault:
high discharge temperature
Discharge Temperature Sensor is defective Check sensor
Condenser Fans not operating or are run-
ning backwards
Check fans
Coils dirty Check and clean coils
High superheat Measure superheat with gauges and
thermocouple. Determine cause
System fault:
high motor temperature
High motor temperature input from one of the
sensors
Refrigerant charge low. Check subcooling
Excess charge in system, High discharge
pressure. Check subcooling
High Superheat. Drain or feed valves not
controlling. Isolate cause
Motor sensor reading incorrectly. Program
panel to ignore a single sensor
Economizer solenoid energized at low
speeds. Valve is leaking through
System fault:
low suction pressure
Low charge Check subcooling
Transducer reads incorrectly Check transducer against a gauge
Suction temp. sensor reads incorrectly Check sensor against a thermocouple
Low flow Check flow
Condenser drain valve not operating Check drain valve operation.
Check superheat
Condenser or drain valve defective Check drain valve operation
check superheat
System fault:
discharge pressure limiting
Discharge transducer is defective Check transducer against a gauge
Ambient temp. very high Normal operation
Fans not operating Check fan operation
Remote or local discharge pressure
load limiting is programmed
Normal operation
System fault:
low economizer superheat
Economizer line temperature sensor is
defective
Check temperature sensor
Economizer transducer is defective Check transducer against a gauge
Economizer feed valve malfunction Check economizer feed valve operation
Economizer line solenoid purge valve
malfunction
Check economizer line solenoid purge
valve operation
Note: Always remove power to the chiller and ensure the DC Bus voltage has bled off.