11 Troubleshooting
Installer and user reference guide
36
5TMV1B
VRV IV-S system air conditioner
4P404224-1 – 2015.03
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+
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 connector
X106A for M1F
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
page 26
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.
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.
11.2
Precautions when troubleshooting
WARNING
▪ When carrying out an inspection on the switch box of
the unit, always make sure that the unit is disconnected
from the mains. Turn off the respective circuit breaker.
▪ When a safety device was activated, stop the unit and
find out why the safety device was activated before
resetting it. NEVER bridge safety devices or change
their values to a value other than the factory default
setting. If you are unable to find the cause of the
problem, call your dealer.
DANGER: RISK OF ELECTROCUTION
WARNING
Prevent hazard due to the inadvertent resetting of the
thermal cut-out: this appliance must NOT be supplied
through an external switching device, such as a timer, or
connected to a circuit that is regularly turned ON and OFF
by the utility.
DANGER: RISK OF BURNING
11.3
Solving problems based on error
codes
In case of a displayed malfunction code, perform correcting actions
as explained in the malfunction code table.
After correcting the abnormality, press BS3 to reset the malfunction
code and retry operation.
INFORMATION
If a malfunction occurs, the error code is displayed on the
user interface of the indoor unit.
