Daikin VRV IV Series - Checklist for Yearly Maintenance of the Heat Exchanger Unit; About Service Mode Operation; To Use Vacuum Mode

21 | Maintenance and service
Installer and user reference guide
122
RKXYQ5T8+8T7Y1B + RDXYQ5T8+8T7V1B
VRV IV heat pump for indoor installation
4P499898-1B – 2021.12
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. If the voltage
measured is still higher than 50 V DC, discharge the capacitors in a safe
manner by using a dedicated capacitor discharge pen to avoid possibility of
sparking.
A2P
C+
C−
A1P
A1P
A3P
8 HP5 HP
TP1 TP2
3 To prevent damaging the PCB, touch a non-coated metal part to eliminate
static electricity before pulling out or plugging in connectors.
For details refer to the wiring diagram labelled on the back of the service cover.
21.3 Checklist for yearly maintenance of the heat exchanger unit
Check the following at least once a year:
▪ Heat exchanger.
The heat exchanger 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.
21.4 About service mode operation
Refrigerant recovery operation/vacuuming operation is possible by applying setting
[2‑21]. Refer to "18.2Making field settings"[499] 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.
21.4.1 To use vacuum mode
1 When the unit is at standstill, activate setting [2‑21] to start vacuuming mode.
Model Result
5HP When confirmed, the expansion valves (in the indoor
unit, compressor unit and heat exchanger unit) 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.