Leak Test And Vacuum Drying; Pipe Insulation; Checking Of Unit And Installation Conditions; Stop Valve Operation Procedure - Daikin RXQ5M9W1B Installation Manual

6.4. Leak test and vacuum drying

The units were checked for leaks by the manufacturer.
See figure 9 and refer to "Additional refrigerant charge" on page 11
for nomenclature of the parts in figure 9.
• Confirm that the gas and liquid line stop valves are firmly closed
before pressure test or vacuuming. Refer to
procedure" on page 10.
• Make sure that valve A is completely open.
Air tight test and vacuum drying
Air tight test: Make sure to use nitrogen gas. (For the service
port location, refer to the "Caution" label attached on the front
panel of the outdoor unit.)
1
2
Pressurize the liquid and gas pipes to 4.0 MPa (40 bar) (do not
pressurize more than 4.0 MPa (40 bar)). If the pressure does not
drop within 24 hours, the system passes the test. If the pressure
drops, check where the nitrogen leaks from.
Vacuum drying: Use a vacuum pump which can evacuate to
–100.7 kPa (5 Torr, –755 mm Hg)
1. Evacuate the system from the liquid and gas pipes by using a
vacuum pump for more than 2 hours and bring the system to
–100.7 kPa. After keeping the system under that condition for more
than 1 hour, check if the vacuum gauge rises or not. If it rises, the
system may either contain moisture inside or have leaks.
2. Following should be executed if there is a possibility of moisture
remaining inside the pipe (if piping work is carried out during the
raining season or over a long period of time, rainwater may enter the
pipe during work).
After evacuating the system for 2 hours, pressurize the system to
0.05 MPa (vacuum break) with nitrogen gas and evacuate the
system again using the vacuum pump for 1 hour to –100.7 kPa
(vacuum drying). If the system cannot be evacuated to –100.7 kPa
within 2 hours, repeat the operation of vacuum break and vacuum
drying.
Then, after leaving the system in vacuum for 1 hour, confirm that the
vacuum gauge does not rise.
NOTE Make sure to perform airtightness test and vacuum
drying using the service ports of the stop valve shown
in the table below.
RX(Y)Q5~16 Liquid line stop valve
RXYQ18~48 Gas line stop valve

6.5. Pipe insulation

After finishing the leak test and vacuum drying, the piping must be
insulated. Take into account the following points:
Make sure to insulate the connection piping and refrigerant
branch kits entirely.
Be sure to insulate liquid and gas piping (for all units).
Use heat resistant polyethylene foam which can withstand a
temperature of 70°C for liquid side piping and polyethylene foam
which can withstand a temperature of 120°C for gas side piping.
If you think the temperature and the relative humidity around the
cooling pipes might exceed 30°C and RH 80%, reinforce the
insulation of the cooling pipes (at least 20 mm thick).
Condensation might be formed on the surface of the insulation.
If there is a possibility that condensation on the stop valve might
drip down into the indoor unit through gaps in the insulation and
piping because the outdoor unit is located higher than the indoor
unit this must be prevented by sealing up the connections. See
figure 8.
RXQ5~10 + RXYQ5~48M9W1B
VRVII System air conditioner
4PW21816-1A
"Stop valve operation
1 Electric box lid
2 Caution label location
A One outdoor unit installed
B When multiple outdoor units installed
1 Liquid line stop valve
2 Gas line stop valve
3 Indoor -outdoor interconnection piping
4 Sealing up treatment
5 Heat insulator
For cooling only units, insulation which can withstand 70°C is
also sufficient for gas side piping.
Be sure to insulate local pipes, as touching them can
cause burns.

6.6. Checking of unit and installation conditions

Be sure to check the following:
1 Make sure there is no faulty power wiring or loose nuts. See
"7. Field wiring" on page
2 Make sure there is no faulty transmission wiring or loose nuts.
See "7. Field wiring" on page
3 Make sure there is no faulty refrigerant piping. See
"6. Refrigerant piping" on page
4 Make sure piping size is correct. See
material" on page 4.
5 Make sure insulation work is done. See
page 10.
6 Make sure the insulation resistance of the main power circuit is
not deteriorated.
Using a megatester for 500 V, check that the insulation
resistance of 2 MΩ or more is attained by applying a voltage of
500 V DC between the power terminals and earth. Never use
the megatester for the transmission wiring (between outdoor
and indoor unit, outdoor and COOL/HEAT selector, etc.).

6.7. Stop valve operation procedure

Do not open the stop valve until steps
"6.6. Checking of unit and installation conditions" on
page 10 are completed. If the stop valve is left open
without turning on the power, it may cause refrigerant to
build up in the compressor, leading to insulation
degradation.
Introduction
Confirm the sizes of the stop valves connected to the system
referring to the table below.
RX(Y)Q5 RX(Y)Q8 RX(Y)Q10 RXYQ12
Liquid line stop
Ø9.5
valve
Gas line stop valve Ø15.9
(*) The model RX(Y)Q8 supports on-site piping of Ø19.1 by the accessory pipes.
(†) The model RXYQ12~16 supports on-site piping of Ø28.6 by the accessory pipes.
12.
12.
4.
"6.1. Selection of piping
"6.5. Pipe insulation" on
RXYQ14
Ø12.7
(*) (†)
Ø22.2 Ø25.4
Installation manual
1~6 of
RXYQ16
10