Panasonic U-72MF2U9 Service Manual page 81

7. Charging Compressor Oil
7. Charging Compressor Oil
Next, follow the instructions in "4-2-1. Cooling operation (for all units)" at the outdoor unit where oil will be charged,
and start cooling operation at all units. After the operating conditions were stabilized, open each valve (Hi-side
manifold gauge, upper valve and lower valve) in sequence as follows.
1. Open the valve on the high-pressure side of the manifold gauge.
2. Open the upper valve.
3. Open the lower valve.
When this is done, the refrigerant pressure from operation forces the oil out of the oil charge tank, and oil is charged
into the outdoor unit from the low-pressure outlet port. Occasionally close the upper valve on the top of the oil charge
tank (only this valve) and shake the tank to check the amount of remaining oil.
Process
Oil charging
Oil charge completed
Refrigerant recovery
(oil-charging tank inside)
Type: 72, 96
Low-pressure outlet port
(for ø5/16" (ø7.94mm)-
dia connector)
High-pressure outlet port
(for ø5/16" (ø7.94mm)-
dia connector)
Liquid tube service port
(for ø5/16" (ø7.94mm)-
dia connector)
Completing oil-charging
To terminate the oil charging work, do as follows:
To end the charge process, first close the valve on the Hi-side manifold gauge. Then wait approximately 60
seconds in order to vaporize the refrigerant in the charge tank. Then fully close the lower valve.
Refrigerant recovery (oil-charging tank inside)
Finally, connect the refrigerant recovery unit to the Lo-side manifold gauge, shut down all indoor and outdoor units,
and then recover the remaining refrigerant in the oil-charging tank. Perform these procedures quickly and securely
so that no air can enter them. Then, charge the necessary amount of new refrigerant by referring to the "Installation
Instructions" that came with the outdoor unit.
NOTE
To determine the completion of refrigerant recovery, follow the instructions that came with the refrigerant recovery unit.
Hi-side
manifold gauge manifold gauge
Open
(No connection)
Close*
(No connection)
Close (Connect to refrigerant
recovery tank)
Connect from
here to refrigerant
recovery unit
Discharge tube service port
(for ø5/16" (ø7.94mm)-
dia connector)
Suction tube service port
(for ø5/16" (ø7.94mm)-
dia connector)
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Outdoor Unit Repair Procedures
Outdoor Unit Repair Procedures
Operating valve
Lo-side
Upper valve
Close
Open
Close
Open
Open
Open
DPR
Manifold
Upper side
gauge
valve
Lo Hi
Lower side
valve
Fig. 12
3WAY VRF SYSTEM
2WAY SYSTEM
Lower valve
Open
Close after approx.
60 seconds
Close
Close
Close
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3
4
5
6
7
8
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