Haier MRV 5-RC VP1-112B Service Manual page 78

10.3. Installation procedure
A. Refrigerant pipe connection
Pipe connection method:
• To ensure the efficiency, the pipe should be as short as possible.
• Daub the refrigerant oil on the connector and the flare nut.
• When bending the pipe, the bending semi-diameter should be as
large as possible against the pipe being broken or bent.
• When connecting the pipe, aim at the center to thread the nut by
hand and tighten it with the double spanners.
• Fastening torque please refers to "pipe specs and fastening
torque" on page 15.
• Don't let the impurity such as sand, water etc into the pipe.
Antifouling measures refer to Page 13.
Cautions in piping installation:
1. When welding the pipe with hard solder, charge nitrogen into the pipe against oxidation. The pressure gauge
should be set at 0.02MPa.Perform the procedure with nitrogen circulation. Otherwise, the oxide film in the pipe
may clog the capillary and expansion valve resulting in accident.
2. The refrigerant pipe should be clean. If the water and the other impurity enter the pipe, charge the nitrogen to
clean the pipe. The nitrogen should flow under the pressure of about 0.5MPa and when charging the nitrogen,
stop up the end of the pipe by hand to enhance the pressure in the pipe, then loose the hand (meanwhile stop up
the other end).
3. The piping installation should be executed after closing the stop valves.
4. When welding the valve and the pipe, cool down the valve with wet towel.
5. When the connection pipe and the branch pipe need to be cut down, please use the special shears and do not
use the saw.
6. When welding copper pipe, use the phosphor copper welding rod without any welding flux. (welding flux will
damage the piping system. The welding flux containing chlorine will corrode pipe, especially, the welding flux with
fluorin will damage refrigeration oil.)
Pipe material and specs selection
1. Please select the refrigerant pipe of the below material.
Material: the phosphoric oxidize seamless copper pipe,
model: C1220T-1/2H (diameter is over 19.05); C1220T-0(diameter is below 15.88).
2. Thickness and specs:
Confirm the pipe thickness and specs according to the pipe selection method(the unit is with R410A, if the
pipe over 19.05 is O-type, the pressure preservation will be bad, thus it must be 1/2H type and over the min.
thickness.
3. The branch pipe and the gather pipe must be from Haier.
4. When installing the stop valve, refer to the relative operation instruction.
5. The pipe installation should be in the allowable range.
6. The installation of branch pipe and gather pipe should be performed according to the relative manual.
Anti-fouling measures
First, clean the pipe.
Position Installation period
More than 1 month
Outdoor
Less than 1 month
Indoor Nothing to do with period
When fastening and loosing the nut,
operate with double spanners, because
only one spanner cannot execute firmly.
If threading the nut as not aiming at the
center, the screw thread will be damaged,
further it will cause leakage.
Measures
Flat the pipe end
Flat the pipe end or seal with adhesive tape
75
Spanner
Connector
Nut
Spanner