Evacuation Of The Equipment - Panasonic CU-4E23QBR Service Manual

Cutting and Flaring the Piping
1. Please cut using pipe cutter and then remove the burrs.
2. Remove the burrs by using reamer. If burrs is not removed, gas leakage may be caused.
Turn the piping end down to avoid the metal powder entering the pipe.
3. Please make flare after inserting the flare nut onto the copper pipes.

10.4 Evacuation of the Equipment

WHEN INSTALLING AN AIR CONDITIONER, BE SURE TO EVACUATE THE AIR INSIDE THE INDOOR UNIT AND
PIPES in the following procedure.
1. Connect a charging hose with a push pin to
the Low side of a charging set and the service
port of the gas side 3-way valve.
Be sure to connect the end of the
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charging hose with the push pin to the
service port.
2. Connect the center hose of the charging set to
a vacuum pump.
3. Turn on the power switch of the vacuum pump
and make sure that the needle in the gauge
moves from 0 cmHg (0 MPa) to –76 cmHg
(–0.1 MPa). Then evacuate the air
approximately ten minutes.
4. Close the Low side valve of the charging set
and turn off the vacuum pump. Make sure that
the needle in the gauge does not move after
approximately five minutes.
Note : BE SURE TO TAKE THIS
PROCEDURE IN ORDER TO
AVOID REFRIGERANT GAS
LEAKAGE.
5. Disconnect the charging hose from the
vacuum pump and from the service port of the
3-way valve.
6. Tighten the service port caps of gas side
3-way valve at a torque of 18 N•m with a
torque wrench.
7. Remove the valve caps of both of the gas side
and liquid side 3-way valve. Position both of
the valves to "OPEN" using a hexagonal
wrench (4 mm).
8. Mount valve caps onto the gas side and liquid
side of the 3-way valve.
Be sure to check for gas leakage.
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
If gauge needle does not move from 0 cmHg (0 MPa) to -76 cmHg (-0.1 MPa), in step 3 above take the following measure:
- If the leak stops when the piping connections are tightened further, continue working from step 3.
- If the leak does not stop when the connections are retightened, repair the location of leak.
- Do not release refrigerant during piping work for installation and reinstallation.
- Take care of the liquid refrigerant, it may cause frostbite.
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