Carrier XCT7 Installations- Und Benutzerhandbuch Seite 28

Installation Procedure
B. Leakage Test
1. The outdoor unit has undergone the leakage test in the factory. The pipe should also undergo leakage tests indi-
vidually and should not be tested after connecting it with the stop valve.
2. Please refer to the figure below to charge the nitrogen into the unit to take a test. Never use chlorine, oxygen or
flammable gases in the leakage test. Apply pressure both on the gas pipe and the liquid pipe.
3. Apply pressure step by step to the target pressure.
a. Apply pressure 0.5MPa for more than 5 minutes and confirm if the pressure goes down
b. Apply pressure 1.5MPa for more than 5 minutes and confirm if the pressure goes down
c. Apply pressure to the target pressure (4.15MPa)and record the temperature and the pressure.
d. Leave it at 4.15MPa for over a day, if the pressure does not reduce, the test is passed. Meanwhile, when the tem-
perature changes by a degree, the pressure will change to 0.01MPa as well. Correct the pressure.
e. After confirmation of a- d, if the pressure reduces, then there is a leakage. Check the brazing position and the
flared position by applying the soap lather. Modify the leakage point and take another leakage test.
4. After the leakage test, execute the evacuation
Nitrogen
C. Evacuation
Evacuate at the check valve of the liquid stop valve and at both sides of the gas stop valve. The oil equalization pipe
must also be vacuumed (execute at the oil equalization pipe and check valve respectively).
Operation Procedure:
If the vacuum pointer rises, it shows there is water or leakage in the system. Please check and modify it, and then evacuate again.
Since the unit uses refrigerant R41OA, the below issues should be paid attention to:
• To prevent the oil from entering the pipe, please use the special tool for R41OA, especially for the gauge manifold
and charging hose.
• To prevent the oil from entering the refrigerant cycle, please use the anti-counter-flow adapter.
• When maintaining the outdoor unit, release the refrigerant from the check valve. During vacuum evacuation, set
the relative dip switch. For details, refer to the code section.
Tighten torque as the table below:
Stop valve diameter (mm)
Ø 6.35
Ø 9.52
Ø 12.7
Ø 15.88
Ø 19.05
After reaching -101KPa or less
(below -755mmHg), let the vacu-
um pump keep running continu-
ously for over an hour.
Fastening torque (N.m)
14-18
34-42
49-61
68-82
84-98
To indoor--+
Gauge manifold
Lo handle Hi handle
Leave it for over an
hour, vacuum point-
er does not arise.
Fastening angle (°)
45-60
30-45
30-45
15-20
15-20
21
+-11
Recommended tool length (mm)
150
200
250
300
300