About Checking The Refrigerant Piping; Checking Refrigerant Piping: General Guidelines - Daikin CO2 Conveni-pack LRYEN10A7Y1 Installer And User Reference Manual

16 | Piping installation

16.4.1 About checking the refrigerant piping

16.4.2 Checking refrigerant piping: General guidelines

Installer and user reference guide
84
▪ If installed, see the installation manual of the pressure reduction kit.
▪ Only use R744 dedicated tools (such as gauge manifold and charge hose) that are
designed to withstand high pressures and which will prevent water, dirt or dust
entering the unit.
CAUTION
Do NOT open the stop valve until you have measured the insulation resistance of the
main power supply circuit.
CAUTION
ALWAYS use nitrogen gas for leak tests.
Checking the refrigerant piping involves:
▪ Checking for any leakages in the refrigerant piping.
▪ Performing vacuum drying to remove all moisture, air or nitrogen in the
refrigerant piping.
If there is a possibility of moisture being present in the refrigerant piping (for
example, water may have entered the piping), first carry out the vacuum drying
procedure below until all moisture has been removed.
All piping inside the unit has been factory tested for leaks.
Only field installed refrigerant piping needs to be checked. Therefore, make sure
that all the outdoor unit stop valves are firmly closed before performing leak test
or vacuum drying.
NOTICE
Make sure that all (field supplied) field piping valves are OPEN (not outdoor unit stop
valves!) before you start leak test and vacuuming.
For more information on the state of the valves, refer to
refrigerant piping: Setup" [
Connect the vacuum pump through a manifold to the service port of all stop valves
to increase efficiency (refer to
NOTICE
Use a 2-stage vacuum pump with a non-return valve or a solenoid valve that can
evacuate to a gauge pressure of –⁠ 1 00.7 kPa (−⁠ 1 .007 bar)(5 Torr absolute).
NOTICE
Make sure the pump oil does not flow oppositely into the system while the pump is
not working.
NOTICE
Do NOT purge the air with refrigerants. Use a vacuum pump to evacuate the
installation.
4
85].
"16.4.3 Checking refrigerant piping:
"16.4.3 Checking
4
Setup" [ 85]).
LRYEN10A7Y1+LRNUN5A7Y1
CO₂ Conveni-Pack outdoor unit
4P605460-1 – 2020.08