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Installation and maintenance instructions 0020257297_06
5.8
Connecting the refrigerant pipes
1
2
1.
Apply a drop of flare oil to the outsides of the pipe
ends.
2.
Connect the hot gas pipe
(2)
.
3.
Tighten the flare nut. Use pliers to hold the service
valve in place while doing so.
Product
Pipe diameter
Tightening torque
VWL 35/5 and
VWL 55/5
1/2 "
50 to 60 Nm
VWL 75/5 to
VWL 125/5
5/8 "
65 to 75 Nm
4.
Connect the liquid pipe 1.
5.
Tighten the flare nut. Use pliers to hold the service
valve in place while doing so.
Product
Pipe diameter
Tightening torque
VWL 35/5 and
VWL 55/5
1/4 "
15 to 20 Nm
VWL 75/5 to
VWL 125/5
3/8 "
35 to 45 Nm
5.9
Checking the refrigerant circuit for tightness
1.
Ensure that the two isolation valves on the outdoor unit
are still closed.
2.
Observe the maximum operating pressure in the refri-
gerant circuit.
N
2
3
4
1
3.
Connect a refrigerant fitting
(2)
with a ball valve
(3)
to
the maintenance connection for the hot gas pipe.
4.
Connect the refrigerant fitting with a ball valve
(1)
to a
nitrogen cylinder
(4)
. Use dry nitrogen.
5.
Open both of the ball valves.
6.
Open the nitrogen cylinder.
–
Test pressure: 2.5 MPa (25 bar)
7.
Close the nitrogen cylinder and the ball valve
(1)
.
–
Waiting period: 10 minutes
8.
Check all of the connections in the refrigerant circuit for
tightness. Use leak detection spray for this.
9.
Observe whether the pressure is stable.
Result 1:
The pressure is stable and no leaks were found:
▶
Completely drain the nitrogen gas via the refriger-
ant fitting.
▶
Close the ball valve
(3)
.
Result 2:
The pressure drops or a leak is found:
▶
Eliminate the leakage.
▶
Repeat the test.
5.10
Evacuating the refrigerant circuit
Note
During evacuation, residual moisture is removed
from the refrigerant circuit at the same time. The
length of the process depends on the residual
moisture and the outdoor temperature.
1.
Ensure that the two isolation valves on the outdoor unit
are still closed.
3
4
5
1
2
2.
Connect a refrigerant fitting
(3)
with a ball valve
(4)
to
the maintenance connection for the hot gas pipe.
3.
Connect the refrigerant fitting with a ball valve
(2)
to a
vacuum gauge
(1)
and a vacuum pump
(5)
.
4.
Open both of the ball valves.
5.
First test
: Switch on the vacuum pump.
6.
Drain the refrigerant pipes and the indoor unit's plate
heat exchanger.
–
Absolute pressure to be reached: 0.1 kPa
(1.0 mbar)
–
Running time of the vacuum pump: 30 minutes
7.
Switch off the vacuum pump.
–
Waiting period: 3 minutes
8.
Check the pressure.
Result 1:
Pressure is stable:
▶
The first test is complete. Start with the second test.
Result 2:
The pressure increases and there is a leak:
▶
Check the flare connections on the outdoor unit and
indoor unit. Eliminate the leakage.
Summary of Contents for VWL 105/5 AS S2
Page 203: ......
