Daikin REYQ96MTJU, Инструкция по проектированию, установке и испытаниям, Страница: 159 / 236

Si39-406 Refrigerant Piping
Installation Manual REYQ96MTJU 153
6.4 Leak Test and Vacuum Drying
The units were checked for leaks by the manufacturer.
Confirm that the valves are firmly closed before pressure test or vacuuming.
To prevent entry of any impurities and ensure sufficient pressure resistance, always use the special
tools dedicated for R410A.
Air tight test and vacuum drying
„
Air tight test: Make sure to use nitrogen gas.
(For the service port location, refer to the "Caution" label attached on the front panel [right] of
the outdoor unit.)
Pressurize the liquid, suction gas and discharge gas pipes to 551 psi
(do not pressurize more than 551 psi). If the pressure does not drop within 24 hours, the system
passes the test. If the pressure drops, check where the nitrogen leaks from.
„
Vacuum drying: Use a vacuum pump which can evacuate to -14.6 psi.
1. Evacuate the system from the liquid, suction gas and discharge gas pipes by using a
vacuum pump for more than 2 hours and bring the system to -14.6 psi. 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.
2. Following should be executed if there is a possibility of moisture remaining inside the pipe (if
piping work is carried out during the raining season or over a long period of time rainwater
may enter the pipe during work).
After evacuating the system for 2 hours, pressurize the system to 7.25psi (vacuum break)
with nitrogen gas and evacuate the system again using the vacuum pump for 1 hour to -14.6
psi (vacuum drying). If the system cannot be evacuated to -14.6 psi within 2 hours, repeat
the operation of vacuum break and vacuum drying.
Then, after leaving the system in vacuum for 1 hour, confirm that the vacuum gauge does
not rise.
Note: Make sure to perform air tight test and vacuum drying using the service ports of the shutoff valve
shown in the table below.
Shutoff valve
operation
procedure Introduction
Confirm the sizes of the shutoff valves connected to the system referring to the table below.
1
3
2
1. [Service precautions]
Label location
2. Electric parts box lid
3. [Caution]
Label location
One outdoor unit installed:
In case of REYQ96MTJU Liquid line shutoff valve
Discharge gas line shutoff valve
Suction gas line shutoff valve
Q96 type
Liquid line shutoff valve
φ
3/8"
Suction gas line shutoff valve
φ
7/8"
Discharge gas line shutoff valve
φ
3/4"