Daikin RXYQ96PYDN Service Manual page 238

SiUS34-801A_b
10.2.3 Air Tight Test and Vacuum Drying
Note:
<Needed tools>
Gauge manifold
Charge hose valve
Vacuum pump
<The system for air tight test and vacuum drying>
Note:
VRVIII R-410A Heat Recovery 60Hz
After finishing piping work, carry out air tight test and vacuum drying.
Always use nitrogen gas for the air-tightness test.
Absolutely do not open the shutoff valve until the main power circuit insulation measurement
has been completed. If you measure after the shutoff valve is opened, it will cause the insulation
value to drop.
• To prevent entry of any impurities and to ensure sufficient pressure resistance,
always use the special tools dedicated for R-410A.
• Use a charge hose that has a pushing stick for connecting to the service ports
of shutoff valves or refrigerant charge port.
• The vacuum pump for vacuum drying should be able to lower the pressure to
–14.6 psi.
• Take care the pump oil never flows backward into the refrigerant pipe during the
pump stops.
Referring to figure 25, connect a nitrogen tank, refrigerant tank, and a vacuum pump to the
outside unit.
The refrigerant tank and the charge hose connection to refrigerant charge port or the valve A in
figure 25 are needed in 10.2.6 Additional Refrigerant Charge and Check Operation.
REYQ72~120PYDN
REYQ72~144PTJU
Gauge manifold
R-410A tank (with siphon) Vacuum pump
REMQ72~120PYDN
REMQ72~120PTJU
Gauge manifold
R-410A tank (with siphon) Vacuum pump
The air-tightness test and vacuum drying should be done using the service ports of equalizer
pipe, HP/LP gas pipe, suction gas pipe and liquid pipe shutoff valve.
See the [R-410A] Label attached to the front plate of the outside unit for details on the location
of the service port (see figure in page 238)
See [Shutoff valve operation procedure] in 10.2.6.1 Before working for details on handling
the shutoff valve.
The refrigerant charge port is connected to unit pipe.
When shipped, the unit contains the refrigerant, so use caution when attaching the charge hose.
Refrigerant charge port
HP/LP gas pipe shutoff valve
Suction gas pipe shutoff valve
Liquid pipe shutoff valve
Charge hose
Valve B
Valve C
Valve A
: Field piping
: Gas flow
Equalizer pipe shutoff valve
HP/LP gas pipe shutoff valve
Suction gas pipe shutoff valve
Charge hose
Liquid pipe shutoff valve
Refrigerant charge port
Valve A
Valve B
Valve C
: Field piping
: Gas flow
figure 25
Test Operation
Outside unit
To BS (or indoor) unit
: Shutoff valve
( )
: Service port
Outside unit Outside unit
: Shutoff valve
To BS
( : Service port
(or indoor) unit
)
223