(2) Connect the indoor unit 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.
(Abnormal sound may occur due to the vibration of the piping. Pay special attention in case of short
piping length.)
(3) Connect the gauge manifold using charging hoses with a vacuum pump or a nitrogen cylinder to the
check joints of the liquid line and the gas line stop valves.
Perform the air-tight test.
Connect a manifold gauge to the check joints of the liquid and gas stop valves in the outdoor unit.
Do not open the stop valves. Apply nitrogen gas pressure of
4.15MPa
.
12
. Additional Refrigerant Charge
12.1 Air-Tight Test
(1) Check to ensure that the stop valves are closed completely before air-tight test.
< Tightening Check of Stop Valves >
a) After connecting the pipe, remove the cap of stop valve for high pressure gas,
low pressure gas (heat recovery system only) and liquid gas.
Tighten the open-close spindle in the close direction with a torque *1).
*1)
< Gas Valve >
< Liquid Valve >
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.
b) Perform the air-tight test after the above check.
Gas Valve
kBtu/h
Tightening Torque
a (N-m)
76 to 114
18 to 22
136 to 170
20 to 25
Stop Valve for High Pressure Gas
and Low Pressure Gas
76 to
96
18 to 22 N-m
114
to
154
20 to 25 N-m
Stop Valve for Liquid Gas
7 to 9 N-m
Cap
Tightening Torque: 50 to 58N-m
Check Joint for Service Port
Only the charging hose
can be connected.
Tightening Torque
:
9 to 14N-m
Hexagonal Wrench
O-ring
(Rubber)
Refrigerant Pressure
To open or close
spindle valve
Spindle Valve
Counterclockwise...Open
Clockwise...............Close
Tightening Torque: a N-m
O-ring
Hexagonal Wrench
Check Joint for Service Port
Only the charging hose
can be connected.
Tightening Torque
:
14 to 18 N-m
Refrigerant
Pressure
Cap
Tightening Torque: 33 to 42 N-m
Refrigerant Piping
To open or close
spindle valve
Spindle Valve
Counterclockwise...Open
Clockwise...............Close
Tightening Torque: 7 to 9 N-m
122
