Daikin RXYQ96PYDN Service Manual page 92

SiUS34-801A_b
Note:
<Air tight test>
Pressurize the liquid pipe, suction gas pipe, HP/LP gas pipe and equalizer pipe from the service
ports of each shutoff valve to 478 psi (do not pressurize more than 478 psi). If the pressure does
not drop within 24 hours, the system passes the test.
If there is a pressure drop, check for leaks, make repairs, and perform the airtight test again.
<Vacuum drying>
Evacuate the system from the liquid pipe, suction gas pipe, HP/LP gas pipe and equalizer pipe
shutoff valve service ports by using a vacuum pump for more than 2 hours and bring the system to
–14.6 psi or less. 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.
Note:
If moisture enters the piping, use the following instructions: ( For example, if working in a
rainy season takes long enough that condensation may form on the inside of the pipes,rain
might enter the pipes during work.)
After evacuating the system for 2 hours, pressurize the system to 7.25 psi (vacuum break) with
nitrogen gas and evacuate the system again using the vacuum pump for 1 hour to –14.6 psi or less
(vacuum drying). If the system cannot be evacuated to –14.6 psi within 2 hours, repeat the
operation of vacuum break and vacuum drying.
After leaving the system in vacuum for 1 hour, confirm that the vacuum gauge does not rise.
10.2.4 Pipe Insulation
VRVIII R-410A Heat Pump 60Hz
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 at right)
See [Shutoff valve operation procedure] in 10.2.5.1
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.
Insulation of pipes should be done after performing 10.2.3 Air Tight Test and Vacuum Drying.
Always insulate the liquid piping, the HP/LP gas piping, the gas piping, the equalizer pipe,
(between the outside units for the outdoor multi system) and these pipe connections.
Be sure to insulate the HP/LP gas piping as the suction pipe because the suction gas follows in
the HP/LP gas piping when the system is whole cooling mode.
Be sure to use the insulation that is designed for use with HVAC Systems.
Reinforce the insulation on the refrigerant piping according to the installation environment.
Condensation might form on the surface of the insulation. Refer to the following standards:
Ambient temperature : 86°F, humidity : 75% to 80% RH : min. thickness : 9/16 inches.
If the ambient temperature exceeds 86°F and the humidity 80% RH, then the minimum
thickness is 3/4 inches.
See the Engineering data book for details.
Test Operation
[R-410A] Label
[R-410A] Label
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RXYQ144PTJU Only
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