Panasonic U-4LE2E5 Service Manual & Test Run Service Manual page 73

3. Recovering Refrigerant
3-2-3. Refrigerant recovery procedures (2): Indoor unit with no ball valve equipped
Refrigerant in all indoor units and the refrigerant tubing circuit can be pumped into the outdoor unit. The maximum
refrigerant storage capacity per a single outdoor unit is approx. 6.7 kg. Thus, in order to collect all refrigerant from
the system, a separate refrigerant recovery unit is necessary. Follow these procedures to correctly perform pump
down.
Perform work correctly, according to the work procedures given below.
1 Connect the manifold gauge to the high- and low-pressure outlet ports on the outdoor unit where pump down
will be performed. Be sure that no air enters the tubing at this time.
2 Follow the instructions in "3-2-1. Cooling operation (for all units)" and operate all units in Cooling mode for
approximately 10 minutes. Then fully close the liquid tube valve on the outdoor unit where pump down will be
performed.
3 When the high-pressure gauge reaches 2.8 MPa or higher, or the low-pressure gauge reaches 0.5 MPa or
below, at the outdoor unit where pump down is being performed, press the ON/OFF button on the outdoor
unit maintenance remote controller to stop operation at all units. Then immediately fully close the gas tube
valve on the outdoor unit where pump down is being performed.
* If the outdoor unit maintenance remote controller is unavailable, short-circuit the STOP pin.
4 Using hoses with Schrader-type push-to-release valves, connect the manifold gauge valves to the gas tube
service port, the liquid tube service port to undergo pump down. (Fig. 4)
CAUTION
5 Use hoses to connect the manifold gauge valves, refrigerant recovery unit, and refrigerant recovery cylinder.
Quickly connect each part to prevent air from entering the tubing.
6 Recover remaining refrigerant from the inter-unit tubing and indoor units using the refrigerant recovery unit.
NOTE
To determine the completion of refrigerant recovery, follow the instructions that came with the refrigerant recovery unit.
Remaining refrigerant in the system may cause internal pressure. Check that each
valve on the manifold gauge is tightly closed. A Schrader-type push-to-release
valve is provided for each connection port.
Outdoor Unit Repair Procedures
3 - 7
Mini VRF SYSTEM
3