Daikin VRV II Series, Инструкции по проектированию, установке и тестированию, Страница: 181 / 242

Si39-303
Installation Manual 175
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 insure 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 and gas pipes to 3.8MPa (38bar) (do not pressurize more than 3.8MPa
(38bar)). 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 –100.7kPa (5Torr, –
755mmHg).
1. Evacuate the system from the liquid and gas pipes by using a vacuum pump for more
than 2 hours and bring the system to
–100.7kPa. 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 0.05MPa (vacuum
break) with nitrogen gas and evacuate the system again using the vacuum pump for 1
hour to
–100.7kPa (vacuum drying). If the system cannot be evacuated to –100.7kPa 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.
Notes: Make sure to perform airtightness test and vacuum drying using the service ports of the shutoff
valve shown in the table on the bellow.
Shutoff valve operation procedure
Introduction
Confirm the sizes of the shutoff valves connected to the system referring to the table on the
below.
1. [Service precautions]
Label location
2. Electric box lid
3. [Caution]
Label location
1
3
2
One outdoor unit installed: In case of
RXYQ5-16MY1B Liquid line shutoff valve
Gas line shutoff valve
When multiple outdoor units installed:
In case of RXYQ18-48MY1B
Liquid line shutoff valve
Gas line shutoff valve
Oil-equalizing line shutoff valve
Q5 type Q8 type Q10 type Q12 type Q14 type Q16 type
Liquid line
shutoff valve
φ
9.5
φ
12.7
Gas line
shutoff valve
φ
15.9
φ
22.2
(The model Q8
supports onsite
piping of
φ
19.1 by the
accessory pipes)
φ
25.4
(The model Q12·14·16 supports
onsite piping of
φ
28.6 by the
accessory pipes)