Liebert DM Series, Руководство пользователя

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60 Chapter 7 Troubleshooting
DM Series 16kW Air Conditioner User Manual
Symptom Possible causes Handling method
Low exhaust
pressure
Water flow too big or temperature of input
water too low (water-cooled)
Adjust the water flow regulator
Check the cooling water system
Refrigerant leaked Locate the leakage point, repair it and add refrigerant
Fan speed controller of outdoor unit is faulty,
while the output voltage remains 100%,
regardless of the change of condensing
pressure (air-cooled)
If the fan speed controller is found faulty, replace it
The suction and
exhaust pressures
do not change after
startup
Compressor reversed or compressor internal
air tightness failed
If compressor reversed, exchange any two L lines of the
compressor. If the compressor internal air tightness failed,
replace the compressor
Low suction
pressure or liquid
returned
Insufficient refrigerant in the system Check for leaks. Seal the leaking point and add refrigerant
Air filter too dirty Replace the air filter
Filter drier clogged Replace the filter drier
Improper superheating degree
Regulate by strictly following the adjusting procedures of
the thermal expansion valve
Sensor of the expansion valve faulty Replace the expansion valve
Improper air flow distribution Check the air supply and return system
Low condensing pressure Check for condenser fault
Belt slipped Check the belt and make necessary adjustment
Compressor too
noisy
Liquid returned
Refer to the handling methods of
“Low suction pressure or
liquid returned
”
Bearing worn out due to insufficient lubricant Add lubricant
Fixture of compressor or pipes loosened Fasten the fixture
Compressor
over-temperature
Too high compression ratio
Check the settings of the HP switch and LP switch, and
make sure the condenser is not clogged
Check that the fans of the evaporator and condenser are
normal
Suction temperature too high
Regulate the expansion valve or add proper amount of
refrigerant
Table 7-3 Troubleshooting of dehumidification system
Symptom Possible causes Handling method
Dehumidification
ineffective
No dehumidification demand from the control
system
Check the control system
Compressor contactor does not close Refer to the compressor related Table 7-2
Compressor does not start, fuse blown or
circuit breaker tripped
Refer to the compressor related Table 7-2
Or check the fuse, or the circuit breaker and the contacts,
and check the line voltage
Hot gas bypass valve not closed (single
compressor system)
Check the control circuit related to the hot gas bypass
valve
Table 7-4 Troubleshooting of infrared humidifier
Symptom Possible causes Handling method
Humidiifcation
ineffective
No water in the
water pan
Check the water supply
Check the water supply solenoid valve
Check the state of the high water-level switch / water-level regulating valve
Check that the water supply pipe is not clogged
No humidification
demand
Check the state of the controller
The humidification
contact does not
close
Check the contactor, and check the circuit voltage of the fuse or circuit breaker
Check the opened safety devices of the humidifier: water pan over-temperature
protection switch and lamp over-temperature protection switch. Use a jumper to
shot terminals P35-6 and P35-5. If the contactor closes, replace the
series-connected safety device, and remove the jumper
Humidifier lamp
burned
Replace the lamp