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RTAC-SVX01F-EN 161
Maintenance Procedures
1. To measure oil level, use the oil drain valve on the oil line and a service valve on
the discharge line. This measurement can only be made when the circuit is not
running.
Note: The level is measured from the bottom of the separator and 1” must be
subtracted for the thickness of the bottom plate.
2. The initial oil charge should be approximately at the level in the above chart. This
is the approximate oil level if all the oil is in the oil lines, filter and oil sump and the
unit is in vacuum so that there is no refrigerant dissolved in the oil.
3. After the unit has run for a while, the oil level in the sump can vary greatly.
However, if the unit has run “normal” conditions for a long time the level should
resemble the level in the above chart. (+1” to – 4” (25 to -101mm) is acceptable.)
The field charging procedure depends on the circumstances that resulted in the need
for oil charge.
1. Some service procedures may result in loss of small quantities of oil which must
be replaced (oil analysis, filter replacement, re-tubing the evaporator, etc.).
2. Additionally, some maintenance procedures may result in virtually all of the oil
being removed (compressor motor burn or total removal of the charge to trouble
shoot a unit).
3. Finally, leaks may result in a loss of oil that must be replaced.
Factory (initial) Oil Charging Procedure
The initial charging procedure should be followed any time the unit is new or has had
all of the oil removed.
4. If the isolation valves is closed, then the charge may be trapped in the evaporator.
In either case, the high side of the system should not be pressurized.
5. The oil line shut off valve must be open to allow the oil to pass into the oil lines
and the oil separator.
6. The oil charging port is a ¼” (6mm) flare fitting with a schrader valve that is on the
side of the oil filter housing. This is the port that must be used to add oil into the
compressor so that the filter and lines are full at the first start of the compressor.
7. On single compressor circuits all the oil should be put into the circuit through the
oil charging port on the compressor filter housing. On two compressor circuits
put approximately ½ of the oil into the unit through each of the two oil charging
ports on the two compressors.
8. Oil may be put into the unit using either of two methods:
Table 38 Oil Charging Data
Circuit
(Tons)
Approximate sump oil level after
running “normal” conditions
(in)
Normal quantity of oil in refrigera-
tion system (evaporator/condenser)
lb (gal)
70 7 1.1 (0.14)
85 6 1.1 (0.14)
100 7 1.8 (0.23)
120 7 1.8 (0.23)
170 8 3.5 (0.44)
200 8 3.5 (0.44)
240 8 3.5 (0.44)