Panasonic U-4LE1E5, Service Manual, Page: 39 / 133

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Mini VRF SYSTEM
Outdoor Unit Repair Procedures
5. Evacuating System
(1)
(2)
(3)
(4)
(5)
(6)
This procedure is carried out to ensure there is no remaining refrigerant or other gases (nitrogen, etc.) in the
repaired outdoor unit and tubing.
5-1. Evacuating Repaired Outdoor Unit
Check that each service valve of the gas line, and the liquid line in the outdoor unit are fully closed.
* If the AP pins (CN-AP) on the outdoor control PCB have already been short-circuited, steps (2) and (5) are
not necessary.
Turn off power to the outdoor unit to be evacuated.
Connect the manifold gauge valves to the high- and low-pressure sensor outlets of the outdoor unit.
Connect the manifold gauge valves to the vacuum pump.
Short-circuit the AP pins on the outdoor control PCB and turn on power to the repaired outdoor unit.
By short-circuiting the AP pins and turning on power to the outdoor unit, all
electronic expansion valves in the outdoor unit are forcibly opened and any
remaining nitrogen gas can be recovered. Failure to perform this procedure
may result in nitrogen gas remaining in the refrigerant circuit and causing
operating problems. Therefore, never skip this step.
To ensure proper evacuation, refer to the operating instructions that came
with the vacuum pump.
Run the vacuum pump and continue evacuation until the vacuum condition falls to less than –101 kPa
(–755 mmHg, 5 Torr).
5-2. Evacuating Refrigerant Tubing Between Indoor and Outdoor Units
Refer to the “Installation Instructions” that came with the outdoor unit.
CAUTION
CAUTION
Vacuum pump
Fig. 2-7
Manifold
gauge
Low-pressure outlet port
(For ø7.94 mm connector)
Lo Hi
High-pressure outlet port
(For ø7.94 mm connector)
SM830195-01̲Mini VRF SYS.indb 11 SM830195-01̲Mini VRF SYS.indb 11 2011/12/20 16:31:16 2011/12/20 16:31:16