Panasonic U-72MF2U9 Technical Data Manual page 54

5. HOW TO INSTALL THE OUTDOOR UNIT
Precautions for brazing
Be sure to replace the air inside the tube with nitrogen to prevent
oxide film from forming during the brazing process. Be sure to use
a damp cloth or other means to cool the valve unit during brazing.
Work method
Brazing locations
1
CAUTION
2
3
4
5
6
7
8
9
Field-supply tube Remote valve
Taping
1. Be sure to use nitrogen. (Oxygen, CO
2. Use a pressure-reducing valve on the nitrogen tank.
3. Do not use agents intended to prevent the formation of oxide film.
They will adversely affect the refrigeration oil, and may cause equipment failure.
4. The balance tube is not used if only 1 outdoor unit is installed.
Use the unit in the same conditions as when it was shipped from the factory.
Pressure-reducing
valve (regulator)
, and CFC must not be used.)
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Design of 3WAY VRF SYSTEM