22
Starting up the system
3 STARTING UP THE SYSTEM
3.1 Air evacuation
The presence of air and foreign substances in the
refrigerant circuit can cause abnormal pressure
increases which, in turn, can damage the air conditioner,
reduce its efficiency and cause injury. Use a vacuum
pump and the manifold pressure gauge assembly to
evacuate the refrigerant circuit to expel all moisture and
non-condensable gases.
Evacuation should be performed at the initial installation
and each time the unit is moved.
l
WARNING
BEFORE COMPLETING THE EVACUATION
– Check that both high pressure and low
pressure pipes between the indoor and
outdoor units are connected correctly
as described in section “6 Notions on
refrigerant piping connection”.
– Check that all electrical cables are connected
correctly.
– Ensure that installation of the refrigerant
pipes complies with applicable legislation.
In Europe, the applicable standard is EN378.
– During testing, NEVER bring the product to
a pressure that is higher than the maximum
allowable pressure (as indicated on the
unit's information plate).
Before using the manifold pressure gauge assembly and
vacuum pump, read their respective user manuals for the
correct procedures.
Manifold pressure gauge unit
High pressure gauge
Loading pipe
High pressure
valve
Pressure pipe /
Loading pipe
Vacuum
pump
Low pressure gauge
Low pressure valve
Low pressure valve
-76 cmHg
Fig. 23
1 Connect the manifold pressure gauge assembly
loading hose to the service port on the low pressure
valve of the outdoor unit.
2 Connect another loading pipe between the manifold
pressure gauge assembly and the vacuum pump.
3 Open the low pressure side of the manifold gauge
assembly. Keep the high pressure side closed.
4 Activate the vacuum pump to evacuate the system.
5 Keep the vacuum pump running for at least 15 minutes,
or until the low pressure gauge indicator reads
-76 cmHG (10
-5
Pa).
6 Close the low pressure side of the manifold gauge
assembly and switch off the vacuum pump.
7 Wait 5 minutes, then check that there are no changes
in system pressure.
8 If a pressure change in the system is observed,
refer to paragraph “3.2.2 Checking for gas leaks” for
information on how to search for possible leaks. If the
system pressure remains unchanged, unscrew the
cap from the expansion valve (high pressure valve).
9 Insert a hexagonal key into the expansion valve (high
pressure valve) and open the valve by turning the key
1/4 turn counterclockwise. Check that you can hear
the noise of exiting gas, then close the valve after
5 seconds.
10 Observe the high pressure gauge for one minute to
check that there are no changes in pressure. The
value of the high pressure gauge should be slightly
higher than atmospheric pressure.
11 Disconnect the loading hose from the service door.
12 Using a hexagonal wrench, fully open both the high
pressure and low pressure valve.
13 Close the caps of the three valves by hand (service
port, high pressure, low pressure). If necessary, tighten
them further using a torque wrench.
Flared nut
Valve body
Valve stem
Cap
Fig. 24
m
CAUTION
OPEN THE VALVE STEMS WITHOUT
FORCING
To open the valve stems, turn the hexagonal
wrench until it is against the stop element. Do
not force the valve to open further.
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