Lennox VEPS075N432K, User Manual

Page: 23 / 40

DC Inverter Multi VRF System
17
4.3.7 Thermal Insulation for Pipeline
(1) For multi VRF system, every copper pipe should be labeled so as to avoid misconnection.
(2) At the branch inlet, leave at least 500mm straight pipe section.
(3) Thermal insulation for pipeline
1) To avoid condensate or water leakage on the connection pipe, the gas pipe and liquid pipe
must be wrapped with thermal insulating material and adhesive tape for insulation from the
air.
2) Thermal insulating material shall be able to bear the pipe temperature. For heat pump unit,
liquid pipe should bear 70°C or above and gas pipe should bear 120°C or above. For
cooling only unit, both liquid pipe and gas pipe should bear 70°C or above.
3) Example: Polyethylene foam (bear 120°C or above); foaming polyethylene (bear 100°C or
above)
4) Joints of indoor and outdoor unit should be wrapped with insulating material and leave no
gap between pipe and wall. See Fig.21.
Fig.21
5) Thermal insulating material of branches should be the same as that of the pipeline. The
attached foam of branches cannot be taken as insulating material.
6) When wrapping the tape, the later circle should cover half of the former one. Don’t wrap the
rape too tight, otherwise the insulation effect will be weakened.
7) After wrapping the pipe, apply sealing material to completely seal the hole on the wall.
4.3.8 Support and Protection of Pipeline
(1) Support should be made for hanging connection pipe. Distance between each support cannot
be over 1m.
(2) Protection against accidental damage should be made for outdoor pipeline. When pipeline
exceeds 1m, a pinch board should be added for protection.
4.4 Vacuum Pumping, Refrigerant Adding
4.4.1 Vacuum Pumping
(1) Outdoor unit has been charged with refrigerant before delivery. Field-installed connection pipe
needs to be charged with additional refrigerant.
(2) Confirm whether outdoor liquid and gas valves are closed.
(3) Use vacuum pump to withdraw the air inside indoor unit and connection pipe from the outdoor