Panasonic U-8ME1E8 Installation Instructions Manual page 39

NOT E
The required time in the above table is calculated based on the
assumption that the ideal (or target) vacuum condition is less
than –101 kPa (–755 mmHg, 5 Torr).
(2) When the desired vacuum is reached, close the "Lo"
knob of the manifold valve and turn off the vacuum pump.
Please confirm that the gauge pressure is under –101 kPa
(–755 mmHg, 5 Torr) after 4 to 5 minutes of vacuum pump
operation.
CAUTION
Charging additional refrigerant
● Charging additional refrigerant (calculated from the liquid
tube length as shown in Section "1-8. Additional Refrigerant
Charge") using the liquid tube service valve. (Fig. 6-5)
● Use a balance to measure the refrigerant accurately.
● If the additional refrigerant charge amount cannot be
charged at once, charge the remaining refrigerant in liquid
form by using the gas tube service valve with the system in
cooling operation mode at the time of test run. (Fig. 6-6)
Finishing the job
(1) With a hex wrench, turn the liquid tube service valve stem
counter-clockwise to fully open the valve.
(2) Turn the gas tube service valve stem counter-clockwise to
fully open the valve.
CAUTION
(3) Loosen the charge hose connected to the gas tube service
port (1/4 in.) slightly to release the pressure, then remove
the hose.
(4) Replace the 1/4 in. flare nut and its bonnet on the gas
tube service port and fasten the flare nut securely with an
adjustable wrench or box wrench. This process is very
important to prevent gas from leaking from the system.
(5) Replace the valve caps at both gas and liquid service valves
and fasten them securely.
This completes air purging with a vacuum pump. The air
conditioner is now ready for a test run.
Use a cylinder designed for use
with R410A respectively.
To avoid gas from leaking when
removing the charge hose,
make sure the stem of the gas
tube is turned all the way out
("BACK SEAT" position).
Manifold valve
Pressure
gauge
Lo Hi
Close
Gas
tube
Open
Liquid
tube
Close
Balance
tube
Open
Gas
tube
Close
Liquid
tube
Close
Balance
tube
38
Valve
Liquid
R410A
Close
Outdoor unit
Close
Close
Fig. 6-5
Open
Outdoor unit
Open
Open
Fig. 6-6