Heat recovery units with refrigeration circuit - URX_CF -
29
Selection and installation manual
GB
Diagnosis and trouble-shooting
1. Insufficient air flow rate • Fans rotation speed • Clean the components
too low
increase the fan speed
• Pressure drop of the
distribution system underestimated
• Blocked filters
• Blocked intake grating
• Coil incrustation
2. Excessive air flow rate • Fans rotation speed • reduce the fan speed
too high
• Pressure drop of the
distribution system overestimated
• Filters not fitted • Fit filters
3. No air flow rate
• Power supply off •
Make sure power supply is available
• Electric motor burnt out • Replace the electric motor
4. Abnormal noise • Excessive flow rate • Reduce flow rate
• Bearings worn or defective • Replace bearings
• Foreign objects on the fan blades • Clean blades
5. Water movement • Trap Blocked • Clean trap
• No trap or incorrectly carried out • Use an adequate trap
6. The compressor does not start • Defective connection or contacts open •
Check the voltage and close the contact
• Thermostat does not • System at temperature, no
respond request; check the setting and the
functioning
• Safety device does not • See point 9) and 10)
respond
• Defective compressor • Replace compressor
7. The compressor does not start • Compressor burnt out or seized • Replace compressor
•
Compressor remote control switch de-energised
• Check the voltage across
the operating time of the protection;
automatic compressor shutdown
• Power circuit open • Check why the protection cut in
compressor; automatic shutdown
8. The compressor starts and then stops • Defective compressor remote control switch • Check and if necessary replace it
• Defective compressor •
Check and if necessary replace it
9. The compressor does not start due to •Pressure switch out or order • Check and replace
the intervention of the high pressure • Excessive refrigerant • Discharge excess gas
switch
• Presence of incondensable gas • Refill the circuit after having
in the refrigerating circuit discharged and placed in vacuum.
•
The condensate coil is not sufficiently
• See point 1)
covered in air
• Blocked refrigerant filter • Check and replace