Klimor EVO-S COMPACT, Operation And Maintenance Manual, Page: 54 / 88

52
EVO-S COMPACT
COMPACT AIR HANDLING UNIT
OPERATION AND MAINTENANCE MANUAL
8. LIST OF MOST COMMON FAULTS
Table 19 List of most common faults in the units
Lp Item AHU opera-
tion of
Symptoms of improper
the AHU
Cause Method Removal
1.
Filtering and mixing
block
Limited airflow rate
Excessive contamination of the preliminary or fine filter Wash or replace with a new one
Casing leakage Tighten clams at the covers
2. Fan block
Limited airflow rate Faulty fan's flexible connector Apply a patch or replace with a new one
No air flow
Motor failure Fix the failure or replace with a new one
No power supply to the electric motor Fix the failure at the switchgear board or power lead
Air damper stuck in closed position Fix the failure
Excessive noise level
Failure of the fan or motor bearing Replace with a new one
Mechanical failure of the rotor Fix the failure or replace with a new one
Loose screw connections Tighten bolts and nuts
Excessive vibrations
Faulty shock absorbers Replace with a new one
Loose rotor at the shaft Fix the failure or replace with a new one
3. DX Cooling block
Excessive air temperature at the
AHU outlet
Incorrect adjustment of the thermostatic valve (not
enough medium delivered to the cooler)
Re-adjust
Contaminated filter at the DX cooler supply Clean the filtering element or replace with a new one
Faulty thermostatic valve or control valve Replace the valve with a new one
Oiled up air cooler Remove oil from the cooler by reducing the overheating level
Air in the cooler, too low water temperature at the supply Bleed the cooler, check the cause of low water temperature
Cooler frosting Too low medium evaporation temperature Rise medium evaporation temperature
Escaping freon Leakage at screwed or soldered connections Locate the leakage and seal it properly
4. Cooling block
Excessive air temperature at
the outlet
Not enough water delivered to the cooler Adjust the thermostatic valve setting
Too low pressure of water delivered to the cooler
Check position of the fully open cut-off valves at the
supply pipe
Air in the cooler
Check position of the fully open cut-off valves at the outlet
pipe and bleed the cooler
Too low air temperature at the
AHU outlet
Too much water delivered to the cooler Adjust the thermostatic valve setting
5. Humidification block
Too low air humidity at the
AHU outlet
Not enough steam or water delivered by the humidifier Check the nozzles condition and clean them
Too low pressure of delivered water
Check operation of the solenoid valve or control valve,
reduce pressure at the control valve, check the cause of too
low pressure of delivered water
Too high air humidity at the outlet
Too much steam or water delivered by the humidifier Or reduce pressure of delivered water
Clogged drainage pipe Check and clean (with compressed air)
6.
Silencing and
separation block No control over air temperature
and humidity at the AHU outlet
Faulty thermostat Replace with a new one
Faulty hygrostat
Adjust the setting in accordance with the operation manual
or replace with a new one
NOTE:
ALL WORKS RELATED TO REPAIR AND ADJUSTMENT OF THE AIR HANDLING UNIT POWER SUPPLY SYSTEMS SHOULD
BE PERFORMED IN ACCORDANCE WITH THE OPERATING MANUAL OF THE ENTIRE AIR CONDITIONING SYSTEM.