Design of 3WAY VRF SYSTEM
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7
6
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4
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6. AIR PURGING
Fig. 2-33
Fig. 2-34
(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
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.
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
run. (Fig. 2-34)
Close the valve on the cylinder containing R410A.
Finishing the job
(1)
(2)
(3)
(4)
(5)
With a flathead screwdriver, turn the liquid tube
service valve counter-clockwise to fully open the
valve.
Turn the all service valve counter-clockwise to fully
open the valve.
Close all stop valves and loosen the “Lo” knob of
the manifold valve.
Loosen the charge hose connected to all service
port, then remove the hose.
Replace all valve caps at all service ports and fasten
them securely.
This completes air purging with a vacuum pump.
The air conditioner is now ready for a test run.
CAUTION
Use a cylinder designed for
use with R410A.
Valve
Liquid
Manifold valve
Pressure
gauge
Lo
Hi
Outdoor unit
Close
Open
Discharge
tube
Suction
tube
Liquid
tube
Close
Close
Balance
tube
Close
Close
Close
Close
R410A
Outdoor unit
Open
Close
Discharge
tube
Suction
tube
Liquid
tube
Open
Close
Balance
tube
Open
Close
Open
Open
TD831158-00̲3WAY̲VRF̲SYS.indb 46
TD831158-00̲3WAY̲VRF̲SYS.indb 46
2012/01/23 17:30:20
2012/01/23 17:30:20
Summary of Contents for U-72MF1U9
Page 118: ...Section 8 TENTATIVE ...