Carrier XCT7 Installations- Und Benutzerhandbuch Seite 18

Installation procedure
A. Refrigerant pipe connection
Pipe connection method:
• To ensure 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 bent semi-diameter should be as
large as possible against the pipe being broken or bent.
• When connecting the pipe, aim at the centre to thread
the nut by hand and tighten it with a double spanner.
• For fastening the torque, please refer to "pipe specs
and fastening torque" on page 15.
• Do not let impurities such as sand, water, etc. into the pipe.
For antifouling measures, refer to page 13
Cautions in piping installation:
1.When welding the pipe with hard solder, charge nitrogen into the pipe to prevent 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 accidents.
2.The refrigerant pipe should be clean. If water or other impurities enter the pipe, charge nitrogen to clean
it. The nitrogen should flow under the pressure of about 0.5Mpa and when charging nitrogen, close
one end of the pipe by hand to enhance the pressure, then loosen your hand (close up the other end
meanwhile).
3 Piping installation should be done after the stop valves are closed.
4 When welding the valve and pipe, cool down the valve with a wet towel.
5.When the connection pipe and the branch pipe need to be cut down, please use special shears and not a
saw.
6.When welding the copper pipe, use the phosphorised copper welding rod without any welding flux.
(welding flux will damage the piping system). The welding flux containing chlorine will corrode the pipe
and that with fluorine will damage the refrigeration oil.
Pipe material and specs selection
1.Please select the refrigerant pipe in the below material.
Material: phosphoric oxidised seamless copper pipe, model: C1220T-1/2H (diameter over 19.05); C1220T
0(diameter below 15.88).
2.Thickness and specs:
Confirm the pipe thickness and specs according to the selection method (the unit uses R410A. If the pipe over
19.05 is 0-type, the pressure preservation will be bad; thus, it must be 1/2H type and over the minimum
thickness.
3. The branch pipe and the gather pipe must be from Carrier.
4. When installing the stop valve, refer to the relevant instructions.
5. The pipe installation should be in the permissible range.
6. The branch pipe and gather pipe should be installed according to the relevant instructions.
When fastening and loosening the nut,
operate with a double spanner, because a
single spanner is not firm enough.
Spanner
Spanner
If threading the nut aiming away from
the center, the screw thread will be
damaged; it will also cause leakage.
11
Connector
Nut