Flooded Type Water Cooled Screw Chiller Technical M
anual
44
Conduct physical and chemical analysis on refrigeration oil to judge water content and
acidity of refrigerant in unit;
Check tightness of all electrical joints that may be loose in control cabinet, startup
cabinet and motor.
2.2.5 Annual Maintenance
Check and analyze record table of operating parameters;
Check oil level and conduct physical and chemical analysis on refrigeration oil; Replace
refrigeration oil of the same grade if oil is emulsified.
Replace filter of refrigeration oil when necessary. Maintenance personnel should check
this item.
Dismantle connecting pipe at outlet of safety valve at last once a year and check valve
body carefully to see if there is corrosion, rust, scale and leakage inside. Replace safety
valve in case of corrosion or leakage. Maintenance personnel should check this item.
Verify set value of high pressure switch of condenser and ensure high pressure switch
acts at 1.8MPa.
Check scale formation degree of pipe pass of condenser. Evaporator that connects open-
type system should also be checked. According to result of checking, it can be determined
that if cleaning cycle and treatment of water in water loop are suitable; if serious scale
formation is found, clean pipe pass. Clean heat transfer pipe at least once a year with
rotary cleaning equipment. If water is polluted, it’s necessary to clean more frequently.
Ultrahigh condensing pressure and insufficient cooling capacity of unit are usually
caused by scale in pipe or air in unit. Compare outlet temperature of cooling water with
refrigerant temperature of condenser. If the difference between them is more than 6
℃
,
scale may have formed in condensation pipe.
Note: during cleaning heat transfer pipe, it’s necessary to use dedicated brush to prevent
scratching and scraping pipe wall. No wire brush is allowed to use.
Maintenance personnel should detect insulation resistance among motor winding and
grounding resistance of winding.
2.2.5 Maintenance Every Three Years
Items of the above-mentioned annual maintenance and check.
Contact qualified maintenance organization such as AUKS local customer
