Daikin Sensira Series, Service Manual

Page: 136 / 172

3 | Third party components
Service manual
136
FTXF20~71A + FTXF20~25B + FTXF20~42C + ATXF20~71A + ATXF20~42C
+ RXF20~71A + RXF20~60B + RXF20~42C + ARXF20~71A + ARXF20~42C
Split Sensira R32
ESIE18-12E – 2021.02
CAUTION
Some outdoor units are equipped with a low pressure switch to protect the
compressor by switching it off. NEVER short‑circuit the low pressure switch during
pump down operation.
1 Remove the refrigerant connection cover, see "2.10 Plate work" [ 4 101].
2 Remove the cap from the stop valves.
3 Perform pump down operation, see installer reference guide for the correct
procedure.
4 After 5~10 minutes (after only 1~2 minutes in case temperature <–10°C),
close the liquid stop valve using a hexagonal wrench.
5 Check the manifold if vacuum is reached. Close the gas stop valve and stop
forced cooling operation.
Refrigerant piping repair
▪ Make sure to cover open pipe ends during repair so no dust or moisture can
enter.
▪ Make sure to re‑apply insulation removed during repair.
▪ Pipe expansion / flare making:
- Remove any burrs on the cut surface using the correct tool such as reamer or
scraper (note that excessive deburring can thin the pipe walls and cause
cracking of the pipe).
- Make sure the flare has the correct size (use a flare gauge).
- Make sure no particles remain in the piping.
- Apply just a drop of refrigerant oil on the inner surface of the flare.
- Make sure the flare connection is tightened with the correct torque (torque
values refer to installation manual).
▪ Brazing:
- Use the correct brazing tool.
- Use a phosphor copper filler metal (silver composition of 0 to 2%). Do not use
flux material.
- Flush the piping before brazing with nitrogen to avoid oxidation of the inside of
the copper tubes (nitrogen purity ≥99.99%).
3.3 External factors
3.3.1 Checking procedures
To check the outdoor temperature
1 The temperature ranges for the different operation modes of the unit can be
found in the databook on Business Portal.
INFORMATION
If the outdoor temperature is outside the range of operation, the unit may NOT
operate or may NOT deliver the required capacity.