Section 7Refrigeration System
7-50
SYSTEM CONTAMINATION CLEANUP
General
This section describes the basic requirements for
restoring contaminated systems to reliable service.
Important
Manitowoc Ice, Inc. assumes no responsibility for
the use of contaminated refrigerant. Damage
resulting from the use of contaminated refrigerant is
the sole responsibility of the servicing company.
Determining Severity Of Contamination
System contamination is generally caused by either
moisture or residue from compressor burnout
entering the refrigeration system.
Inspection of the refrigerant usually provides the first
indication of system contamination. Obvious
moisture or an acrid odor in the refrigerant indicates
contamination.
If either condition is found, or if contamination is
suspected, use a Total Test Kit from Totaline or a
similar diagnostic tool. These devices sample
refrigerant, eliminating the need to take an oil
sample. Follow the manufacturer’s directions.
If a refrigerant test kit indicates harmful levels of
contamination, or if a test kit is not available, inspect
the compressor oil.
1. Remove the refrigerant charge from the ice
machine.
2. Remove the compressor from the system.
3. Check the odor and appearance of the oil.
4. Inspect open suction and discharge lines at the
compressor for burnout deposits.
5. If no signs of contamination are present, perform
an acid oil test.
Check the chart below to determine the type of
cleanup required.
Contamination/Cleanup Chart
Symptoms/Findings Required Cleanup Procedure
No symptoms or suspicion of contamination Normal evacuation/recharging procedure
Moisture/Air Contamination symptoms
• Refrigeration system open to atmosphere for
longer than 15 minutes
• Refrigeration test kit and/or acid oil test shows
contamination
• Leak in water-cooled condenser
• No burnout deposits in open compressor lines
Mild contamination cleanup procedure
Mild Compressor Burnout symptoms
• Oil appears clean but smells acrid
• Refrigeration test kit or acid oil test shows harmful
acid content
• No burnout deposits in open compressor lines
Mild contamination cleanup procedure
Severe Compressor Burnout symptoms
• Oil is discolored, acidic, and smells acrid
• Burnout deposits found in the compressor and
lines, and in other components
Severe contamination cleanup procedure