Panasonic CU-5E34NBE-C Technical & Service Manual page 56

(4) With the "Lo" knob of the manifold valve open and high-pressure valve ("Hi") closed completely, run the vacuum
pump. Run the pump until the pressure is –101 kPa (–76 cmHg). The operation time for the vacuum pump varies
with tubing length and the capacity of the pump. The following table shows the amount of time required for
evacuation:
Table 5
Required time for evacuation when capacity
of 100 liter/h vacuum pump is used
20 min. or more
NOTE
The required time in the above table is calculated
based on the assumption that the ideal (or target)
vacuum condition is around 10 mmHg abs.
(5) With the vacuum pump still running, close the "Lo" knob of the manifold valve. Then stop the vacuum pump.
Fully close the low-pressure valve and stop the vacuum pump. (Wait 1 – 2 minutes and check that the manifold
gauge pointer does not return. If it does return, find and repair the leak, then apply the vacuum again.)
(6) With a hex wrench, turn the valve stem on the narrow tube service valve counterclockwise by 90 degrees (1/4
turn) for 10 seconds, and then turn the stem clockwise to close it again.
Be sure to completely insert
CAUTION
the hex wrench before
attempting to turn the valve.
(7) With a standard screwdriver, turn the wide tube service valve stem counterclockwise to fully open the valve.
(8) Turn the narrow tube service valve stem counterclockwise to fully open the valve.
(9) Loosen the vacuum hose connected to the wide tube service port slightly to release the pressure. Then,
remove the hose.
(10) Leak test all joints at the tubing (both indoor and outdoors) with liquid soap. Bubbles indicate a leak. Be sure to
wipe off the soap with a clean cloth.
If a CFC gas detector is used,
CAUTION
use a special detector for HFC
refrigerant (such as R410A and
R134a).
(11) Replace the flare nut on the wide tube service port and fasten the flare nut securely with an adjustable wrench
or box wrench. Next, mount the valve cap and tighten it with a torque wrench (the cap needs to be tightened
with the torque of 19 N·m (190 kgf · cm) or 24 N·m (240 kgf · cm)). This process is very important to prevent
gas from leaking from the system.
(12) Test run the air conditioner. (See page 19.)
(13) While the air conditioner is running, apply liquid soap to check for any gas leaks around the service valves or
caps.
(14) If there is no leakage, stop the air conditioner.
(15) Wipe off the soap on the tubing.
This completes air purging with a vacuum pump and the air conditioner is ready for actual operation.
14