Checking The Refrigerant Piping; Checking Refrigerant Piping: Setup; To Check For Leaks: Pressure Leak Test; To Perform Vacuum Drying - Daikin SEHVX20BAW Installation And Operation Manual

▪ First cut off the refrigerant liquid piping inside the unit
approximately 7 cm before the clamp and the refrigerant gas
piping 4 cm before the clamp. This is necessary in order to avoid
the piping cutter tool from interfering with the piping. Remove any
burrs from the piping.
▪ Use accessory pipes to connect field refrigerant piping to the
piping connections on the indoor unit. For SEHVX20BAW, after
cutting off the end of both the liquid and gas refrigerant piping,
braze accessory pipe 1 to the liquid connection and accessory
pipe 2 to the gas connection. For SEHVX32BAW, after cutting off
the end of both the liquid and gas refrigerant piping, braze the field
piping directly to the liquid connection and accessory pipe 2 to the
gas connection. For SEHVX40BAW, perform the procedure for
SEHVX20BAW twice. For SEHVX64BAW, perform the procedure
for SEHVX32BAW twice.
NOTICE
After brazing, fix the pipes to the unit using the clamps in
the pipe supports.
a
d
C1
C2
d
g g
C2 C1
e
f
a Indoor unit
b Outdoor unit 1
c Outdoor unit 2 (only in case of SEHVX40+64BAW)
d Refrigerant piping
e Pump
f Switchbox
g Evaporator
NOTICE
When installing the piping between the outdoor and indoor
units, also refer to the figure in
supply and transmission cables" on
SERHQ020~032BAW1 + SEHVX20~64BAW
Split packaged air-cooled water chiller
4P508019-1C – 2018.04
b
VRV
C1
c
VRV
C2
"5.8.4 To connect the power
page 20.
5.5

Checking the refrigerant piping

5.5.1

Checking refrigerant piping: Setup

a
d
b c e
a Pressure reducing valve
b Nitrogen
c Weighing scales
d R410A refrigerant tank (siphon system)
e Vacuum pump
f Charge hose
g Service port for adding refrigerant
h Liquid line stop valve
i Gas line stop valve
j Stop valve service port
k Valve A
l Valve B
m Valve C
Valve
Valve A
Valve B
Valve C
Liquid line stop valve
Gas line stop valve
5.5.2

To check for leaks: Pressure leak test

NOTICE
After all the piping has been connected, make sure there is
no gas leak. Use nitrogen to perform a gas leak detection.
1 Break the vacuum by pressurising with nitrogen gas to a gauge
pressure of 4.0 MPa (40 bar). Never set the gauge pressure
higher than the maximum operation pressure of the unit, i.e.
4.0 MPa (40 bar).
5.5.3

To perform vacuum drying

To remove all moisture from the system, proceed as follows:
1 Evacuate the system for at least 2 hours to a target vacuum of
–⁠ 1 00.7 kPa (–⁠ 1 .007 bar)(5 Torr absolute).
2 Check that, with the vacuum pump turned off, the target
vacuum is maintained for at least 1 hour.
3 Should you fail to reach the target vacuum within 2 hours or
maintain the vacuum for 1 hour, the system may contain too
much moisture. In that case, break the vacuum by pressurising
with nitrogen gas to a gauge pressure of 0.05 MPa (0.5 bar)
and repeat steps 1 to 3 until all moisture has been removed.
NOTICE
In case of SEHVX40+64BAW, perform the operations on
both units.
5.5.4

To insulate the refrigerant piping

After finishing the leak test and vacuum drying, the piping must be
insulated. Take into account the following points:
▪ Be sure to insulate the liquid and gas piping (for all units).
▪ Use heat resistant polyethylene foam which can withstand a
temperature of 70°C for liquid piping and polyethylene foam which
can withstand a temperature of 120°C for gas piping.
5 Installation
i h
g
k
l
m
f j
State of valve
Close
Open
Close
Close
Close
Installation and operation manual
15