Thermo King SB-190 30, Manual

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Refrigeration Maintenance (Rev. 12/03)
59
A system has to run for at least 15 minutes to change the
color of the indicator ring after the moisture content of the
system has been changed. For example, evacuating a system
to remove the moisture will not change the color of the indi-
cator ring until the system has been recharged and then
operated for at least 15 minutes.
REFRIGERANT LEAKS
Use a reliable leak detector (e.g., electronic detector or
Halide torch) to leak test the refrigeration system. Inspect
for signs of oil leakage which is the first sign of a leak in the
refrigeration system.
NOTE: It is normal for compressor shaft seals to have a
slightly oily film.
CHECKING COMPRESSOR OIL
The compressor oil should be checked when there is evi-
dence of oil loss (oil leaks) or when components in the
refrigeration system have been removed for service or
replacement.
To check compressor oil level with an ambient air
temperature above 50 F (10 C):
Install a gauge manifold on the compressor.
Operate the unit on Cool with a 20 psi (138 kPa) minimum
suction pressure and a 185 psi (1275 kPa) minimum dis-
charge pressure for 15 minutes or more.
After the unit has maintained the above conditions for 15
minutes, observe the oil level. The oil should be 1/4 to 1/2
up in the sight glass.
To check compressor oil level with an ambient air
temperature below 50 F (10 C):
Run the unit through a complete defrost cycle. After com-
pleting the defrost cycle, run the unit on Cool for ten min-
utes. Observe the oil level. The oil should be 1/4 to 1/2 up in
the sight glass.
If the box is empty, you can run the unit on the heat cycle
instead of the defrost cycle.
NOTE: Use refrigeration compressor oil ONLY. Polyol
Ester P/N 203-413 is required for R-404A.
ARA035
1
1. Colored Ring
Moisture Indicating Sight Glass
1. Sight Glass
Checking Compressor Oil
1
ARA115