Haier AB242ACBEA Service Manual page 26

5. 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
Check if the pressure drops
The pressure does not drop-passed
The pressure drops-check the leaking point.
From pressurizing to 24 hours later, each 1* difference of ambient temperature
will make 0.01MPa(0.1kg/cm
Checking the leaking point
In the first to third test steps, if the pressure drops, check the leakage in each joint
use sense of hearing, feeling and soap water, etc. methods to find the leaking point.
After confirming the leaking point, welding it again or tighten the nut tightly again.
3-way valve totally closed
(Gas side)
Outdoor
Flare part
Flare part
2-way valve totally closed
(Liquid side)
First step: 0.3MPa (3.
2
0kg/cm g) pressurize
over 3 minutes.
Second step: 1.5Mpa
2
(15kg/cm g) pressurize
over 3 minutes. Large
leakage will be found.
Third step: 3.0 MPa
2
(30kg/cm g) pressurize
about 24 hours. Little
leakage will be found.
2
g) pressure change. It shall be corrected during test.
Low pressure peizometer
High pressure peizometer
VL VH
Discharging valve
Dropping valve
Manhole
Outdoor units
Meter separator
Nitrogen tank