Large Outdoor Unit; Piping Repair Procedures - Daikin R32 Sky-Air RZAG-M Service Manual

ESIE17-08 | Part 3. Repair
C
AUTION
Refer to Installer Reference Guide for 'Pump down operation' procedure.
3. After 5-10 min (after only 1-2 min in case of very low Ta < -10°C), close the liquid stop valve with a hexagonal wrench.
4. Check on manifold if vacuum is reached, close gas stop valve and forced cooling operation.

3.1.3.2. Large outdoor unit

1. Stop all demands for the Daikin unit.
2. Switch OFF / ON the power supply of the outdoor unit.
3. Carry out pump down operation.
C
AUTION
Refer to Installer Reference Guide for 'Pump down operation' procedure.
4. The compressor and outdoor fan will start automatically.
5. Request heating via remote controller to prevent HE freeze-up.
6. a. Check on manifold if vacuum is reached, close gas stop valve and forced cooling operation.
b. Once operation stops (after 3 to 5 minutes), close the liquid and the gas stop valve.
7. Pump down is now finished. U4 may be displayed on the remote controller, this is not a malfunction.
8. (After "pump down" is finished or stopped, keep the circulation pump running for at least 5 minutes.)
9. Switch OFF the power supply of the outdoor unit.
NOTE
• Make sure to re-open both stop valves before restart operation of the unit.
• After a finished or stopped pump down, the unit will perform a test run at first operation (same as during
commissioning).

3.1.4. Piping repair procedures

• Make sure to cover open pipe ends during repair work 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 and use 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 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%).
Page 64
R32 Sky-Air RZAG-M
3.1. Refrigerant repair procedures
15/11/18 | Version 1.1