23 | Maintenance and service
Installer and user reference guide
139
RXMLQ8 + RXYLQ10~14T7Y1B*
VRV IV system air conditioner
4P543427-1A – 2020.10
23 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
In this chapter
23.1 Maintenance safety precautions............................................................................................................................................ 139
23.1.1 To prevent electrical hazards................................................................................................................................. 139
23.2 About service mode operation............................................................................................................................................... 140
23.2.1 To use vacuum mode ............................................................................................................................................. 140
23.2.2 To recover refrigerant............................................................................................................................................ 140
23.1 Maintenance safety precautions
DANGER: RISK OF ELECTROCUTION
DANGER: RISK OF BURNING/SCALDING
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.
23.1.1 To prevent electrical hazards
When performing service to inverter equipment:
1 Do NOT open the electrical component box cover for 10minutes 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 50VDC. 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.