Checking The Refrigerant Piping; About Checking The Refrigerant Piping - Daikin VRV W T-Series Installation Manual

Use the following procedure to remove the pinched piping:
1 Remove the valve cover and make sure that the stop valves are
fully closed.
c
b
a
d
a Service port and service port cover
b Stop valve
c
Field piping connection
d Stop valve cover
2 Connect the vacuuming/recovery unit through a manifold to the
service port of all stop valves.
p < p >
C
(1)
A B
f
a
d
N2 R410A
b c e
a
Pressure reducing valve
b Nitrogen
c Measuring instrument
d Refrigerant R410A tank (siphon system)
e Vacuum pump
f
Liquid line stop valve
g Gas line stop valve
h High pressure/low pressure gas line stop valve
A Valve A
B
Valve B
C Valve C
(1)
D Valve D
(1) Only for heat recovery mode.
NOTE
Do not connect the vacuum pump to the suction gas stop
valve if the unit is intended to run in heat pump mode. This
will increase the risk of unit failure.
3 Recover gas and oil from the pinched piping by using a
recovery unit.
CAUTION
Do not vent gases into the atmosphere.
4 When all gas and oil is recovered from the pinched piping,
disconnect the charge hose and close the service ports
5 Cut off the upper part of the liquid, gas, and high pressure/low
pressure gas stop valve pipes along the black line. Use an
appropriate tool (e.g. a pipe cutter, a pair of nippers).
RWEQ96~432TAYCU
VRV W T-Series water-cooled system air conditioner
4P540122-1B – 2018.11
D
g
h
WARNING
Never remove the pinched piping by brazing.
Any gas or oil remaining inside the stop valve may blow off
the pinched piping.
6 Make sure that no particles remain in the pipe. Blow out any
particles with compressed air.
5 .4

Checking the refrigerant piping

5 .4 .1

About checking the refrigerant piping

Refrigerant piping works are
finished? No
Yes
The indoor units and/or
outside unit were already
No
powered ON?
Yes
Use procedure:
"Method 2: After power ON".
It is very important that all refrigerant piping work is done before the
units (outside or indoor) are powered on.
When the units are powered on, the expansion valves will initialize.
This means that they will close. Leak test and vacuum drying of field
piping and indoor units is impossible when this happens.
Therefore, there will be explained 2 methods for initial installation,
leak test and vacuum drying.
Method 1: Before power ON
If the system has not yet been powered on, no special action is
required to perform the leak test and the vacuum drying.
Method 2: After power ON
If the system has already been powered on, activate setting [2-21]
(refer to "7.2.4 To access mode 1 or 2" on page 35). This setting will
open field expansion valves to guarantee a R410A piping pathway
and make it possible to perform the leak test and the vacuum drying.
NOTE
Make sure that all indoor units connected to the outside
unit are powered on.
NOTE
Wait until the outside unit has finished the initialization to
apply setting [2-21].
5 Installation
Finish piping work.
Use procedure:
"Method 1: Before power ON
(regular method)".
Installation manual
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