Maintenance and service
Installer reference guide
28
RZAG71~Y1
Sky Air Alpha-series
4P573381-1 – 2019.04
9
Maintenance and service
NOTICE
Maintenance MUST be done by an authorized installer or
service agent.
We recommend performing maintenance at least once a
year. However, applicable legislation might require shorter
maintenance intervals.
NOTICE
Applicable legislation on
fluorinated greenhouse gases
requires that the refrigerant charge of the unit is indicated
both in weight and CO
2
equivalent.
Formula to calculate the quantity in CO
2
equivalent
tonnes:
GWP value of the refrigerant × total refrigerant
charge [in kg] / 1000
9.1
Overview: Maintenance and
service
This chapter contains information about:
▪ Maintenance safety precautions
▪ The yearly maintenance of the outdoor unit
9.2
Maintenance safety precautions
DANGER: RISK OF ELECTROCUTION
DANGER: RISK OF BURNING
NOTICE: Risk of electrostatic discharge
Before performing any maintenance or service work, touch
a metal part of the unit in order to eliminate static electricity
and to protect the PCB.
9.2.1
To prevent electrical hazards
When performing service to inverter equipment:
1
Do NOT open the electrical component box cover for
10 minutes after turning off the power supply.
2
Measure the voltage between terminals on the terminal block
for power supply with a tester and confirm that the power supply
is shut off. In addition, measure points as shown in the figure,
with a tester and confirm that the voltage of the capacitor in the
main circuit is less than 50 V DC.
A1P
C–
C+
C–
C+
V1
Y1
3
To prevent damaging the PCB, touch a non-coated metal part
to eliminate static electricity before pulling out or plugging in
connectors.
4
Pull out junction connector X106A (A1P) for the fan motor in the
outdoor unit before starting service operation on the inverter
equipment. Be careful not to touch the live parts. (If a fan
rotates due to strong wind, it may store electricity in the
capacitor or in the main circuit and cause electric shock.)
5
After the service is finished, plug the junction connector back in.
Otherwise the malfunction code E7 will be displayed and
normal operation will not be performed.
For details refer to the wiring diagram labelled on the back of the
service cover.
NOTICE
NEVER directly connect power supply cables to
compressors (U, V, W). This can result in a compressor
burnout.
9.3
Checklist for yearly maintenance
of the outdoor unit
Check the following at least once a year:
▪ Heat exchanger
The heat exchanger of the outdoor unit can get blocked up due to
dust, dirt, leaves, etc. It is recommended to clean the heat
exchanger yearly. A blocked heat exchanger can lead to too low
pressure or too high pressure leading to worse performance.
10
Troubleshooting
10.1
Overview: Troubleshooting
In case of problems:
▪ See
"7.5 Error codes when performing a test run" on page 27
.
▪ See the service manual.
INFORMATION
The outdoor unit can generate some transient noises
during operation. These sounds are NOT system
malfunctions:
▪ A “shah” noise is heard at the start of defrost operation.
This is the sound of the 4-way valve.
▪ A continuous low hissing sound is heard when the
system is in cooling or defrost operation. This is the
sound of refrigerant gas flowing through both indoor
and outdoor units.
▪ A gurgling sound is heard after defrost operation. This
is the sound of refrigerant gas flowing through the
refrigerant pipe system.
▪ A hissing sound which is heard at the start or
immediately after stopping operation or defrost
operation. This is the noise of refrigerant caused by
flow stop or flow change.
This section provides useful information for diagnosing and
correcting certain problems which may occur with the unit. This
troubleshooting and related corrective actions may only be carried
out by the installer or service agent.
Before troubleshooting
Carry out a thorough visual inspection of the unit and look for
obvious defects such as loose connections or defective wiring.
