11 Troubleshooting
Installer and user reference guide
38
RXYSQ4~Y1B
VRV IV-S system air conditioner
4P404676-1A – 2016.03
NOTICE
In Europe, the
greenhouse gas emissions
of the total
refrigerant charge in the system (expressed as tonnes
CO
2
-equivalent) is used to determine the maintenance
intervals. Follow the applicable legislation.
Formula to calculate the greenhouse gas emissions:
GWP value of the refrigerant × Total refrigerant charge [in
kg] / 1000
10.1
Overview: Maintenance and
service
This chapter contains information about:
▪ Preventing electrical hazards when maintaining and servicing the
system
▪ The refrigerant recovery operation
10.2
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.
10.2.1
To prevent electrical hazards
When performing service to inverter equipment:
1
Do not open the electrical component box cover for 10 minutes
after the power supply is turned off.
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
below, with a tester and confirm that the voltage of the capacitor
in the main circuit is less than 50 V DC.
A1P
C–
C+
V1
Y1
C–
C+
A2P
A1P
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 connectors for the fan motors 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.)
Junction connectors
X106A for M1F
X107A for M2F
5
After the service is finished, plug the junction connector back in.
Otherwise the malfunction code
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.
Pay attention to the fan. It is dangerous to inspect the unit while the
fan is running. Make sure to turn off the main switch and to remove
the fuses from the control circuit located in the outdoor unit.
10.3
Checklist for yearly maintenance
of the outdoor unit
Check the following at least once a year:
▪ Outdoor unit 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.
10.4
About service mode operation
Refrigerant recovery operation/vacuuming operation is possible by
applying setting [2‑21]. Refer to
"7.2 Making field settings" on
for details how to set mode 2.
When vacuuming/recovery mode is used, check very carefully what
should be vacuumed/recovered before starting. See installation
manual of the indoor unit for more information about vacuuming and
recovery.
10.4.1
To use vacuum mode
1
When the unit is at standstill, activate setting [2‑21] to start
vacuuming mode.
Result:
When confirmed, the indoor and outdoor unit expansion
valves will fully open. At that moment H1P lights and the user
interface of all indoor units indicate TEST (test operation) and
(external control) and the operation will be prohibited.
2
Evacuate the system with a vacuum pump.
3
Press BS1 to stop vacuuming mode.
10.4.2
To recover refrigerant
This should be done by a refrigerant reclaimer. Follow the same
procedure as for vacuuming method.
NOTICE
Make sure to NOT recover any oil while recovering
refrigerant.
Example:
By using an oil separator.
11
Troubleshooting
11.1
Overview: Troubleshooting
Before troubleshooting
Carry out a thorough visual inspection of the unit and look for
obvious defects such as loose connections or defective wiring.
