Johnson Controls YORK YK Operation Manual page 9

Draining, flushing, and handling refrigerant for the oil system
When needed, use the following procedure to ensure oil quality.
1. Ensure that the chiller refrigerant charge is completely recovered.
2. Completely flush the oil circuit with the new oil type.
a. Drain the existing oil.
b. Fill the oil system with the new oil type.
c. Run the oil pumps for 15 min.
d. Drain this first fill of the new oil type.
e. Ensure that all of the oil piping has completely drained back to the sump.
f. Remove the sump cover.
g. Clean the internal surfaces of the oil sump.
h. Replace the oil filter.
i. Fill the oil system with the required amount of the new oil type.
3. During chiller recharging when a new charge is not used, you must distill the refrigerant
using a vapor charging process from the recovered charge when charging the chiller.
Note: This requirement is in place due to the amount of oil that is entrained for the
refrigerant charge that must be distilled to prevent the previous oil being reintroduced
to the chiller system. Reintroducing the old oil contaminates the new oil.
Oil quality and testing
The oil quality in traditional oil-lubricated chillers is critical. Perform a complete oil analysis on an
annual basis. You can purchase an oil analysis kit P/N 064-54053-000 through the Johnson Controls
parts system.
Aftermarket lubricants may contain additives or other chemical components that can be harmful
to reliable chiller operation. Use the genuine YORK oil specified for the chiller and application when
making replacements.
For a comprehensive oil analysis, complete the following tests:
• Kinematic viscosity at 104°F (40°C) and 212°F (100°C) (ASTM D445)
• Acid number (ASTM D974)
• Particle count
• Metal analysis by mass spectrometer or by sulfated ash procedure (ASTM D874)
• Moisture by the Karl Fischer method
Kinematic viscosity (ASTM D445)
Kinematic viscosity is the property measured when a fixed amount of an oil flows through a
capillary tube under the force of gravity. The viscosity test is an indicator of the oil's resistance to
flow. The test is used to indicate the breakdown of the oil or contamination from another fluid. An
increase or decrease in viscosity can lead to overheating or increased friction, ultimately resulting in
catastrophic failure.
YORK Oil Application, Oil Change Interval, and Oil Quality Limits Replacement Recommendations
CAUTION
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