Compressor Oil Level - Carrier 69NT40-541-001 Operation And Service

7.8.6

Compressor Oil Level

Use only Carrier Transicold approved Polyol Ester Oil (POE) - Castrol-Icematic SW20 compres-
sor oil with R-134a. Buy in quantities of one quart or smaller. When using this hygroscopic oil,
immediately reseal. Do not leave container of oil open or contamination will occur.
a. Checking the Oil Level in the Compressor
1. Operate the unit in cooling mode for at least 20 minutes.
2. Check the front oil sight glass on the compressor to ensure that no foaming of the oil is present after 20
minutes of operation. If the oil is foaming excessively after 20 minutes of operation, check the refrigerant
system for flood-back of liquid refrigerant. Correct this situation before performing the following step.
3. Turn unit off to check the oil level. The correct oil level range should be between the bottom to one-
eighth level of the sight glass. If the level is above one-eighth, oil must be removed from the compressor.
To remove oil from the compressor, follow step d in this section. If the level is below the bottom of the
sight glass, add oil to the compressor following step b below.
b. Adding Oil with Compressor in System
1. The recommended method is to add oil using an oil pump at the oil fill valve (see item 11,
2. In an emergency where an oil pump is not available, oil may be drawn into the compressor through the
suction service valve.
Connect the suction connection of the gauge manifold to the compressor suction service valve port, and immerse
the common connection of the gauge manifold in an open container of refrigeration oil. Extreme care must be taken
to ensure the manifold common connection remains immersed in oil at all times. Otherwise air and moisture will be
drawn into the compressor. Crack the suction service valve and gauge valve to vent a small amount of refrigerant
through the common connection and the oil to purge the lines of air. Close the gauge manifold valve.
With the unit running, frontseat the suction service valve and induce a vacuum in the compressor crank case.
SLOWLY crack the suction gauge manifold valve and oil will flow through the suction service valve into the com-
pressor. Add oil as necessary.
c. Adding Oil to Service Replacement Compressor
Service replacement compressors are shipped without oil. If oil is present in the crankcase, it must be tested to
ensure it is the correct oil and that the moisture level is acceptable.
When adding oil to a service replacement compressor add three liters (6.3 pints) using an oil pump at the oil fill
valve (see item 11, Figure
erant system. Install compressor and check oil level after it is placed in operation. Refer to
d. Removing Oil from the Compressor
1. If the oil level recorded in step a.3 is above one-eighth level of the capacity of the sight glass, oil must be
removed from the compressor.
2. Close (frontseat) the manifold liquid hand valve and pump unit down to 1.2 to 1.3 kg/cm² (2 to 4 psig).
Frontseat the manifold vapor hand valve and slowly bleed remaining refrigerant.
3. Remove the oil drain plug on the bottom plate of the compressor and drain the proper amount of oil from
the compressor to obtain the correct level (maximum is one-eight level of the sight glass). Replace the
plug securely back into the compressor.
4. Repeat step (a) to ensure proper oil level.
T-316
!
7.6). This quantity is recommended to allow for return of any oil that may be in the refrig-
CAUTION
7–16
Figure 7.6).
Section 7.8.6.