Operating The Unit; Maintenance And Service; Overview: Maintenance And Service; Maintenance Safety Precautions - Daikin RYYQ8T7Y1B Installer And User Reference Manual

8.7

Operating the unit

Once the unit is installed and test operation of outdoor unit and
indoor units is finished, the operation of the system can start.
For operating the indoor unit, the user interface of the indoor unit
should be switched ON. Refer to the indoor unit operation manual for
more details.
9

Maintenance and service

NOTICE
Maintenance must be done by an authorised installer or
service agent.
We recommend to do maintenance at least once a year.
However, applicable legislation might require shorter
maintenance intervals.
NOTICE
In Europe, the greenhouse gas emissions of the total
refrigerant charge in the system (expressed as tonnes
CO -equivalent) is used to determine the maintenance
2
intervals. Follow the applicable legislation.
Formula to calculate the greenhouse gas emissions:
GWP value of the refrigerant × Total refrigerant charge [in
kg] / 1000
9.1 Overview: Maintenance and
service
This chapter contains information about:
▪ Preventing electrical hazards when maintaining and servicing the
system
▪ The refrigerant recovery operation
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 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.
RYYQ+RYMQ+RXYQ8~20T7Y1B
VRV IV system air conditioner
4P370475-1C – 2016.11
9 Maintenance and service
8~12 HP
X3A
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 X1A, X2A (X3A, X4A) 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.)
5 After the service is finished, plug the junction connector back in.
Otherwise the malfunction code
user interface or on the outdoor unit 7‑segment display and
normal operation will not be performed.
For details refer to the wiring diagram labelled on the back of the
electrical component box 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.
9.3

About service mode operation

Refrigerant recovery operation/vacuuming operation is possible by
applying setting [2‑21]. Refer to
page 39 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.
9.3.1

To use vacuum mode

1 When the unit is at standstill, set the unit in [2‑21]=1.
Result: When confirmed, the indoor and outdoor unit expansion
valves will fully open. At that moment the 7‑segment display
indication= and the user interface of all indoor units
indicate TEST (test operation) and
the operation will be prohibited.
2 Evacuate the system with a vacuum pump.
3 Press BS3 to stop vacuuming mode.
9.3.2

To recover refrigerant

This should be done by a refrigerant reclaimer. Follow the same
procedure as for vacuuming method.
DANGER: RISK OF EXPLOSION
Pump down – Refrigerant leakage. If you want to pump
down the system, and there is a leakage in the refrigerant
circuit:
▪ Do NOT use the unit's automatic pump down function,
with which you can collect all refrigerant from the
system into the outdoor unit. Possible consequence:
Self-combustion and explosion of the compressor
because of air going into the operating compressor.
▪ Use a separate recovery system so that the unit's
compressor does NOT have to operate.
14~20 HP
RED
BLK
X6A (A6P) X5A (A3P)
will be displayed on the
"7.2 Making field settings" on
(external control) and
Installer and user reference guide
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