T-CU19-JAN24-1
Page 26
Code
Description
Possible Cause
Solution
23
STO detection error
Internal fault
Call for assistance
25
Ground fault
The drive has detected a ground current
too high
Check ground insulation of the motor
and wires.
26
CPU sync error 1
Overload CPU
Call for assistance
27
CPU sync error 2
Loss of data in memory
Call for assistance
28
Drive overload
The current supplied has exceeded the
drive rated current over the maximum time
accepted
Check the compressor model and the
cables.
Service and Maintenance
Disconnect the mains electrical supply and
wait at least 5 minutes for capacitors to fully
discharge before opening the unit for
service/repair.
The condensing units are designed to give long life
operation with minimum maintenance. However, they should
be routinely checked, and the following service schedule is
recommended under normal circumstances:
The removal of the top, side and front panels ensures that all
parts are accessible.
1.
Compressor
–
Inspect at regular intervals.
•
Check for refrigerant leaks on all joints and fittings.
Retighten the valve cap according to
Table 20.
•
Check mountings for tightness and wear.
•
Check operation of crankcase heater.
•
Check electrical connections.
•
Ensure that no abnormal noise or vibration is detected
during the test run.
•
Check the compressor oil levels and top up if required.
2.
Condenser Fan Motor & Blade
–
Clean and inspect at
regular intervals.
•
Check for abnormal noise, vibration, and fan
imbalance.
•
Ensure that the fan motor is clean and spins freely.
•
Check that the condenser fan blade is clean and free
from restriction and damage/imbalance.
Note: The fan motor is pre-lubricated, and factory sealed
so no maintenance is necessary.
3.
Condenser Coil
–
Clean and inspect at regular
intervals.
•
Check and remove the dirt and debris between the fins
using a soft brush, low pressure compressed air/inert
gas or a low-pressure sprayer utilizing clean water. A
suitable chemical coil cleaner may be used as required.
Accumulations of dirt on the condenser face can be
removed with a soft bristle hand brush. When using
liquids, ensure electrical items are isolated and
correctly protected.
•
DO NOT USE HIGH PRESSURE JET WASHERS.
•
Check and remove any obstacles which may hinder the
airflow through the condenser coil.
4.
Frequency Drive
•
Check heat sink and internal fans freely rotating and
dust free.
•
Check on all electrical connections, ensuring screw
terminals are correctly torqued (power terminal: Max.
1.5Nm, auxiliary terminal: Max. 0.5Nm)
5.
Controls
•
Check settings and operation of pressure switches.
•
Check overload setting.
•
Check fan speed control setting and operation.
6.
Power Supply
–
Inspect at regular intervals.
•
Check the running current and voltage for the
condensing unit.
•
Check the electrical wiring and tighten the wires onto
the terminal blocks if necessary.
7.
Refrigerant Charge (Refer Section Refrigerant
Charge)
•
Check the refrigerant charge by ensuring that the
system is operating correctly, the pressures are as
expected and that the liquid line sight glass shows a
full bore of liquid refrigerant.
•
Carry out a full leak test.
8. Unit decommissioning and disposal
•
At the end of the unit’s useful life, a suitably qualified
engineer should decommission it. The refrigerant and
compressor oil are classed as hazardous waste and as
such must be reclaimed and disposed of in the correct
manner, including completion of waste transfer
paperwork. The unit components must be disposed of
or recycled as appropriate in the correct manner.
8.
Warranty
•
The warranty as provided by Daikin on its products is
subject to correct application, siting, and installation
procedures together with subsequent recorded
maintenance/servicing carried out in accordance with
our recommendations. Failure to do so could result in
the withdrawal of our warranty. Please go to our
website for our detailed warranty terms and
conditions:
