Panasonic U-72MF1U9 Technical Data Manual page 60

6. AIR PURGING
(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 –14.7 psig (–755 mmHg, 5 Torr) after 4 to 5
minutes of vacuum pump operation.
Charging additional refrigerant
CAUTION
Charging additional refrigerant (calculated from the
liquid tube length as shown in Section "Additional
Refrigerant Charge (page 2-5)") using the liquid tube
service valve. (Fig. 2-33)
Use a balance or scale to measure the refrigerant
accurately.
1
If the additional refrigerant charge amount cannot be
charged at once, charge the remaining refrigerant in
liquid form by using the suction tube service valve
with the system in Cooling mode at the time of test
2
run. (Fig. 2-34)
Close the valve on the cylinder containing R410A.
Finishing the job
3
(1) With a flathead screwdriver, turn the liquid tube
service valve counter-clockwise to fully open the
valve.
(2) Turn the all service valve counter-clockwise to fully
4
open the valve.
(3) Close all stop valves and loosen the "Lo" knob of
the manifold valve.
(4) Loosen the charge hose connected to all service
5
port, then remove the hose.
(5) Replace all valve caps at all service ports and fasten
them securely.
6
This completes air purging with a vacuum pump.
The air conditioner is now ready for a test run.
7
8
Use a cylinder designed for
use with R410A.
Manifold valve
Pressure
Lo
gauge
Close
Suction
tube
Discharge
tube
Open
Liquid
tube
Close
Balance
tube
Suction
tube
Discharge
tube
Liquid
tube
Balance
tube
2 - 46
Design of 3WAY VRF SYSTEM
Hi
Valve
Liquid
R410A
Close
Close
Outdoor unit
Close
Close
Close
Fig. 2-33
Open
Open
Close
Outdoor unit
Open
Close
Open
Close
Open
Fig. 2-34