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
Be careful not to let foreign matters, such as sands enter the pipe.
(4) Piping connection
Forced fastening without centering
may damage the threads and cause
a gas leakage.
Pipe diameter
Fastening torque
Liquid pipe 6.35mm
Gas pipe 15.88mm
Liquid pipe 9.52mm
Gas pipe 19.05mm
14.2-17.2N.m
61.8-75.4N.m
32.7-39.9N.m
97.2-118.6N.m
Gas pipe 12.7mm
49.5-60.3N.m
screw nut on by hand, refer to Fig.
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
The gas and liquid valve are all in close state. In order to prevent the nitrogen entering the
and liquid valve rods).
Use vacuum pump to perform vacuumizing. It is strictly forbidden to use the refrigerant to
After air tightness test and discharging all the nitrogen, connect the vacuum pump as the
5. Air discharging method
6. Piping and indoor unit vacuumizing
Outdoor
Completely tightened
Completely tightened
Flare part
Outdoor units
Manhole
Discharging valve
3-way valve totally closed
(Gas side)
Low pressure peizometer
High pressure peizometer
Meter separator
Dropping valve
2-way valve totally closed
(Liquid side)
Nitrogen tank
VL VH
Indoor units
Indoor
Flare part
In the first to third test steps, if the pressure drops, check the leakage in each joint use sense
After confirming the leaking point, welding it again or tighten the nut tightly again.
Checking the leaking point
First step: 0.3MPa (3.0kg/cm2g) pressurize over 3 minutes.
Second step: 1.5Mpa (15kg/cm2g) pressurize over 3 minutes. Large leakage will be found.
Third step: 3.0 MPa (30kg/cm2g) pressurize about 24 hours. Little leakage will be found.
From pressurizing to 24 hours later, each 1
difference of ambient temperature will make
2
Check if the pressure drops
The pressure does not drop-passed
The pressure drops-check the leaking point.
mode as the
following figure shown.
circulation system
of outdoor unit, tighten the valve rod before giving pressure (both gas
degree
g) pressure change. It shall be corrected during test.
0.01MPa
(0.1kg/cm
of hearing,
feeling and soap water, etc. methods to find the leaking point.
remove the air
inside the system.
following figure
shown.
-179-
Installation
