Additional Refrigerant Charge; Air-Tight Test - Hisense AVWT-408FHFSHA Installation Manual

7. Additional Refrigerant Charge

7.1 Air-Tight Test

(1)Check to ensure that the stop valves are closed completely before air-tight test.
<Tightening Check of Stop Valves>
After connecting the pipe, remove the cap of stop valve for liquid.
<Gas Valve>
Cap
Tightening torque: b N·m
Allen Wrench
Open/close
spindle valve
O-ring
Spindle Valve
Counterclockwise......open
Clockwise......close
Tightening torque: c ft·lbs
(N·m)
Gas Valve
Model
72~192
(2) Connect the indoor units and the outdoor unit with field-supplied refrigerant piping.
Suspend the refrigerant piping at specified points and prevent the refrigerant piping from touching weak
parts of the building such as wall, ceiling, etc.. Vibration of the piping may give abnormal sound.
(3) Connect the manifold gauge to a vacuum pump or a nitrogen cylinder and the check joint of the
liquid stop valves and gas stop valves with charging hoses.
(4) Apply nitrogen gas pressure of 601psi(4.15MPa).
Do not open the stop valves.
Be sure to use Nitrogen Gas for air-tight test. If other gases such as oxygen gas, acetylene gas or
fluorocarbon gas are accidentally used, it may cause explosion or gas intoxication.
(5) Check for any gas leakage at the flare nut connections, or brazed parts by use of a foaming agent or
gas leak detector.
(6) Mount the piping insulation materials after connecting the pipe.
Procedure
Completion of
Ref. Piping
Check Joint for Service Port
Only the charge hose can be
connected
Tightening torque: a ft·lbs(N·m)
Refrigerant Pressure
Torque a Torque b
Torque c
ft·lbs(N·m)
ft·lbs(N·m) ft·lbs(N·m)
11.1(15) 40.5(55) 22.1(30)
Charging
Nitrogen Gas
Check Joint for Service Port
For charging additional refrigerant only
Valve-closing torque: 11.1ft·lbs (15 N·m)
Cap
Tightening Torque: b N·m
O-ring
Hexagonal Wrench
Used to open/close
spindle valve
Spindle Valve
Counterterclockwise......Open
Clockwise......Close
Tightening Torque: a N·m
Refrigerant Piping
Model
72~96
120
144~192
DANGER
Check of Pressure
Decrease
Fix Leakage
28
<Liquid Valve>
Liquid Valve
Torque a Torque b
ft·lbs(N·m)
ft·lbs(N·m)
5.2(7)
18.4(25)
7.4(10) 22.1(30)
9.6(13) 25.8(35)
Pass
Refrigerant
Pressure