Panasonic CS-VA120KE, Service Manual, Page: 37 / 78

Precautions
· Be sure to read the instructions for the vacuum pump,
vacuum pump adaptor and manifold gauge prior to use,
and follow the instructions carefully.
· Make sure that the vacuum pump is filled with oil up to
the designated line on the oil gauge.
· The gas pressure backflow prevention valve on the
charging hose is generally open during use. When you
are removing the charging hose from the service port, it
will come off more easily if you close this valve.
Fig. 12 Vacuum pump air purging configuration
b. Take special care when doing piping work on rainy days. The entering of moisture will degrade the refrigerating machine oil,
and lead to malfunctions in the equipment.
c. Complete all pipe connections in as short a time as possible. If the pipe must be left standing for a long time after removing
the seal, it must be thoroughly purged with nitrogen, or dried with a vacuum pump.
9.4. INSTALLATION, TRANSFERRING SERVICING
9.4.1. Inspecting Gas Leaks with a Vacuum Pump for New Installations (Using New
Refrigerant Piping))
1. From the viewpoint of protecting the global environment, please do not release refrigerant into the atmosphere.
a. Connect the projecting side (pin-pushing side) of the charging hose for the manifold gauge to the service port of the 3-way
valve. (1)
b. Fully open the handle Lo of the manifold gauge and run the vacuum pump. (2) (If the needle of the low-pressure gauge
instantly reaches vacuum, re-check step a).)
c. Continue the vacuum process for at least 15 minutes, then check to make sure the low-pressure gauge has reached -0.1
MPa (-76 cmHg). Once the vacuum process has finished, fully close the handle Lo of the manifold gauge and stop the
vacuum pump operation, then remove the charging hose that is connected to the vacuum pump adaptor. (Leave the unit in
that condition for 1-2 minutes, and make sure that the needle of the manifold gauge does not return.) (2) and (3)
d. Turn the valve stem of the 2-way valve 90° counter-clockwise to open it, then, after 10 seconds, close it and inspect for a
gas leak (4)
e. Remove the charging hose from the 3-way valve service port, then open both the 2-way valve and 3-way valve. (1) (4) (Turn
the valve stem in the counter-clockwise direction until it gently makes contact. Do not turn it forcefully.)
f. Tighten the service port cap with a torque wrench (18 N m (1.8 kgf m)). (5) Then tighten the 2-way valve and 3-way valve
caps with a torque wrench (42 N m (4.2 kgf m)) or (55 N m (5.5 kgf m)). (6)
g. After attaching each of the caps, inspect for a gas leak around the cap area. (5) (6)
9.4.2. Transferring (Using New Refrigerant Piping)
1. Removing the unit
a. Collecting the refrigerant into the outdoor unit by pumping down
The refrigerant can be collected into the outdoor unit (pumping down) by pressing the TEST RUN button, even when the
temperature of the room is low.
· Check to make sure that the valve stems of the 2-way valve and 3-way valve have been opened by turning them counter-
clockwise. (Remove the valve stem caps and check to see that the valve stems are fully opened position. Always use
a hex wrench (with 4-mm opposing sides) to operate the valve stems.)
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CS-VA70KE / CU-VA70KE / CS-VA90KE / CU-VA90KE / CS-VA120KE / CU-VA120KE