Daikin VRV III RXYQ5-54PY1, Service Manual

Page: 158 / 398

Si34-601A Test Operation
Test Operation 147
1.2.3 Air Tight Test and Vacuum Drying
Note:
„
Always use nitrogen gas for the airtightness test.
„
Absolutely do not open the shutoff valve until the main power ciruit insulation measurement
has been completed. (measuring after the shutoff valve is opened will cause the insulation
value to drop.)
1.2.3.1 Preparations
<Needed tools>
<The system for air tight test and vacuum drying>
•
Referring to figure 28, connect an nitrogen tank, refrigerant tank, and a vacuum pump to the
outdoor unit.
•
The shutoff valve and valve A~C in figure 28 should be open or closed as shown in the table
below.
Note:
„
The airtightness test and vacuum drying should be done using the liquid
side and gas side shutoff valve service ports.
See the [R-410A] Label attached to the front plate of the outdoor unit for
details on the location of the service port (see figure at right).
„
See [Shutoff valve operation procedure] for details on handling the
shutoff valve. (Refer page 149)
„
The refrigerant charge port is connected to unit pipe.
When shipped, the unit contains refrigerant, so use caution when
attaching the charge hose.
Gauge manifold
Charge hose valve
• To prevent entry of any impurities and insure sufficient
pressure resistance, always use the special tools
dedicated for R-410A.
• Use charge hose that have pushing stick for connecting
to service port of shutoff valves or refrigerant charge
port.
Vacuum pump
• The vacuum pump for vacuum drying should be able to
lower the pressure to –100.7kPa
(5 Torr –755mm Hg).
• Take care the pump oil never flow backward into the
refrigerant pipe during the pump stops.
of valve A, B and C and shutoff valves
Valve shutoff valve
A B C Liquid side Gas side
Air tight test, Vacuum drying
(Close valve A and shutoff valves certainly. Otherwise the
refrigerant in the unit are released.)
Close Open Open Close Close
Gouge manifold
Nitrogen
Measur
ing de
vice
R-410A cylinder
(with siphon)
Vacuum pump
Charge
hose
Liquid side
shutoff valve
Gas side
shutoff valve
Shutoff valve
service port
Valve B
Valve C
Valve A
Outdoor
unit
Outdoor
unit
Refrigerant charge port
To indoor unit
Interunit pipings
Gas flow
fig. 28
[Caution] Label