3.7 Oil Cooling Systems
Carlyle 06T semi-hermetic screw compressors
can be operated for most applications without
external oil cooling. 05T open drive screw com-
pressors require external oil cooling any time
the system discharge temperature may exceed
180°F. Carlyle’s Carwin selection software can
be used to estimate the discharge temperature
for a given application.
When an oil cooler is not required, it also elimi-
nates the need for any oil mixing components
to keep the oil within a designated temperature
range when the oil is being returned from an air
cooled oil cooler during low ambient periods.
Operating without an oil cooler does not
change the lubricant recommendations for
R-404A/507. The recommendation is to use
POE 100 or 170 lubricants. For R-22 applica-
tions the recommendation for a lubricant is
POE 170, CPI Solest 170, for all R-22 low,
medium and high temperature applications.
14
When an oil cooler is used with R-22, the
recommendation is to use POE 100 or 170.
Operating without an oil cooler does
impact the system's condenser selec-
tions.
Since the oil cooler removes heat
from the compressor, additional heat will be
transferred to the compressor's heat of
rejection, or condenser load. Current ver-
sions of Carlyle's compressor selection pro-
gram take this into consideration, allowing
selections to be made with or without an
external oil cooler.
Operating without an oil cooler results in little
or no performance change on higher dis-
placement models. The slower rotor speeds
on smaller CFM models results in a discern-
able capacity loss that may require consider-
ation. Current versions of Carlyle's compres-
sor selection program take this into consid-
eration, allowing selections to be made with
or without an external oil cooler.
Allowable Application Range Without Oil Coolers
Application:
Saturated Suction:
Saturated Condensing:
Recommended Oils:
R-404A/507 Low Temp.
-40 F to 0 F
70 F to 120 F
POE 100 or 170
R-404A/507 Medium Temp.
0 F to 50 F
70 F to 130 F
POE 100 or 170
R-134a Medium & High Temp.
-10 F to 50 F
70 F to 150 F`
POE 100 or 170
R-22 Low Temp.
-25 F to 0 F
70 F to 120 F
POE 170*
R-22 Low Temp.
-30 F to -26 F
70 F to 110 F
POE 170*
R-22 Medium & High Temp.
0 F to 50 F
70 F to 130 F
POE 170*
* If oil cooler used, oil can revert to POE 100
