Discharging Compressor Oil - Panasonic U-10MF1E8 Service Manual

3. Discharging Compressor Oil

Discharged oil can be used for checking the condition of the system. Based on the appearance and color of the
discharged oil, a judgment can be made on whether the system is operating normally or not.
3-1. Discharging Oil from Oil Separator
Recover the refrigerant from the outdoor unit following the procedure given in "5. Recovering Refrigerant." Install
hoses as indicated on the equipment and feed nitrogen gas gradually to provide pressure to the system from the
low-pressure outlet and collect oil in a pan or container. (Fig. 6)
CAUTION
Packless valve or the like
Nitrogen gas
3-2. Discharging Oil in Compressor
Recover the refrigerant in the outdoor unit following the procedures in "5. Recovering Refrigerant." Remove the
compressor and discharge the oil in it. Refer to "10. Compressor" for detailed procedures.
3-3. Checking the Oil
Acceptance/rejection criteria for the oil
Condition of
refrigeration cycle
Normal
Abnormal
overheat operation
Brownish /
Motor burnout
* It is difficult to measure the total acid value in the field, therefore oil hue and odor are the rule of thumb. Checking
for carbon deposits and abrasive metal powder can additionally be used to assess the system condition.
• The low-pressure outlet port is at the Lo side of the right side.
• A faulty outdoor unit may remain pressurized. The oil delivery port employs a
Schrader-type push-to-release valve. Be careful to avoid accidental oil release
when using the port.
Container
Manifold gauge
Lo Hi
Condition of oil
Color Odor
Yellowish None
Smells somewhat
Brownish
(not as strong as below)
Pungent / burnt odor
blackish
Outdoor Unit Repair Procedures
Oil delivery port
(For 6.35mm-dia. connector)
Fig. 6
Judgment criteria for changing oil*
Total acid value
0.02 or less
0.06 or over
Changing the oil and system cleaning
with dry-cores are necessary.
Changing the oil and system cleaning
with dry-cores are necessary.
2 - 5
3-WAY SYSTEM
Low-pressure outlet port
(For 7.94mm-dia. connector)
Hue
3.5 or less
4.0 or over
2