American Power Conversion DX 用户手册
79
NetworkAIR FM DX 60 Hz Operation, Maintenance, and Troubleshooting
Suction pressure too
low
low
• Dirty or blocked evaporator coil
• Dirty or blocked air filters
• Low airflow
• Low return air temperature
• Dirty or blocked air filters
• Low airflow
• Low return air temperature
• Low refrigerant charge
• Liquid line filter drier is blocked
• High evaporator superheat
• High evaporator superheat
• Clean evaporator coil.
• Check filters and replace as needed.
• Check for correct airflow setting.
• Verify the return air temperature is not below
• Check filters and replace as needed.
• Check for correct airflow setting.
• Verify the return air temperature is not below
20ºC (68
°
F).
• Check for short cycling of cold supply air.
• Check subcooling and ensure it is at least
• Check subcooling and ensure it is at least
10-15
°
F. Repair leak and recharge system
• Check filter drier for excessive pressure drop.
• Check for proper superheat and TXV
• Check for proper superheat and TXV
operation.
System short of
capacity
capacity
• Low refrigerant charge
• Liquid line filter drier is blocked
• High evaporator superheat
• High evaporator superheat
• Insufficient air quantity across the
evaporator coil
• Excessive outside air infiltration
• Lack of proper room vapor barrier
• Lack of proper room vapor barrier
• Check subcooling and ensure it is at least
10-15
°
F. Repair leak and recharge system.
• Check filter drier for excessive pressure drop.
• Check for proper superheat and TXV
• Check for proper superheat and TXV
operation.
• Check for correct airflow and clean filters.
• Reduce outside air infiltration.
• Install vapor barrier materials on floor, walls,
• Install vapor barrier materials on floor, walls,
and ceiling as needed.
Temperature control
not tight enough
not tight enough
• Excessive outside air infiltration
• Lack of proper room vapor barrier
• Lack of proper room vapor barrier
• Cool/reheat setpoints not close
enough
• Reheat PID loop is not properly
tuned
• Interstage delay is too large
• Return air temperature does not
reflect actual room condition
• Reduce outside air infiltration.
• Install vapor barrier materials on floor, walls,
• Install vapor barrier materials on floor, walls,
and ceiling as needed.
• Check cooling and reheat setpoints and
deadbands.
• Tune the PID loop for accurate reheat
operation.
• Reduce the interstage delay to allow quicker
response to temperature changes.
• Check for short cycling of cold supply air.
• Check air distribution for deficiencies.
• Consider using remote sensor control.
• Check air distribution for deficiencies.
• Consider using remote sensor control.
Note: Be certain to purchase the correct
temperature and humidity probe. Check when
ordering that your equipment is compatible.
temperature and humidity probe. Check when
ordering that your equipment is compatible.
Water carryover
• Dirt or oil residue on evaporator
coil
• Insufficient air quantity across the
evaporator coil
• Excessive airflow across the
evaporator coil
• Blockage in condensate pan or
drain line
• Low return air temperature
• High return humidity
• Excessive outside air infiltration
• Lack of proper room vapor barrier
• Lack of proper room vapor barrier
• Clean the evaporator coil.
• Check for correct airflow and clean filters.
• Reduce airflow to specifications.
• Clean condensate pan and drain line.
• Verify the return air temperature is not below
20ºC (68ºF).
• Check for short cycling of cold supply air
• Lower humidity setpoint.
• Check for short cycling of supply air
• Reduce outside air infiltration.
• Install vapor barrier materials on floor, walls,
• Lower humidity setpoint.
• Check for short cycling of supply air
• Reduce outside air infiltration.
• Install vapor barrier materials on floor, walls,
and ceiling as needed.
Problem
Possible Cause
Corrective Action