Haier AU282AHBEA Service Manual page 199

Piping connection
Connecting method (indoor unit)
Apply refrigerant oil at half union as large and flare nut.
To bend a pipe, give the roundness as possible not to crush
the pipe.
When connecting pipe, hold the pipe centre to centre then
screw nut on by hand, refer to Fig.
Be careful not to let foreign matters, such as sands enter
the pipe.
Forced fastening without centering may
damage the threads and cause a gas
leakage.
Air discharging method
After finishing connection of refrigerant pipe, it shall perform air tightness test.
The air tightness test adopts nitrogen tank to give pressure according to the pipe connection mode as
the following figure shown.
The gas and liquid valve are all in close state. In order to prevent the nitrogen entering the
circulation system of outdoor unit, tighten the valve rod before giving pressure (both gas and liquid
valve rods).
Indoor
Completely tightened
Completely tightened
Indoor units
First step: 0.3MPa (3.0kg/cm
Second step: 1.5Mpa (15kg/cm
Third step: 3.0 MPa (30kg/cm
Check if the pressure drops
If the pressure does not drop, the unit is passed
If the pressure drops, please check the leaking point.
Low pressure gauge
3-way valve totally closed
(Gas side)
Outdoor
Flare part
Flare part
2-way valve totally closed
(Liquid side)
2
g) pressurize over 3 minutes.
2
g) pressurize over 3 minutes. Large leakage will be found.
2
g) pressurize about 24 hours. Little leakage will be found.
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Pipe diameter
Liquid pipe 6.35mm
Liquid pipe 9.52mm
Gas pipe 12.7mm
Gas pipe 15.88mm
Gas pipe 19.05mm
High pressure gauge
Discharging valve
Dropping valve
Mainhole
Outdoor units
Fastening torque
14.2-17.2N . m
32.7-39.9N . m
49.5-60.3N . m
61.8-75.4N . m
97.2-118.6N . m
Meter separator
VLVH
Nitrogen tank