2.11 Motors and power
2.11.1 Compressor drive motor
SX 3
SX 7.5
Rated power [hp]
3.0
7.5
Rated speed [rpm]
3490
3540
Enclosure protection
TEFC
Tab. 13 Compressor drive motor
2.12 Cooling Oil Recommendation
A sticker showing the type of oil filled is located near the oil separator filler.
Information for ordering cooling oil can be found in chapter 13.4.
2.12.1 Basic Information
Lubrication of an air compressor is essential to reliable operation. Carbon and varnish can form in
compressor cooling oils. These deposits block the flow of lubricant and cause excessive wear and
failure of moving parts. Contamination of the lubricant can allow the formation of acids, causing ex‐
tensive internal corrosion. Water may be condensed decreasing the lubricity.
Lubricants in rotary compressors do much more than lubricate. During the compression process, it
acts as a sealant in the airend which is important for maximum efficiency. The lubricant also absorbs
much of the heat of compression to cool the airend and reduce the temperature of the compressed
air. It’s not enough that a compressor cooling oil lubricates well, it must stand up to the heat, pressure
and contaminants that are present in every air compressor.
2.12.2 KAESER Lubricants
KAESER synthetic lubricants should be stored in a protected location to prevent contamination. Do
not re-use drums; flush and send to reconditioner.
Although the KAESER synthetic is not highly flammable, it will burn. While KAESER synthetic com‐
pressor cooling oil is less flammable than equal viscosity mineral oils, it cannot be classified as a fire-
resistant fluid. It has a flash point above 460 °F. Since the user has total control over the conditions
of the compressor lubricant, he assumes total responsibility for its safe usage.
Material Safety Data Sheets are available for each lubricant from your authorized KAESER Service
representative.
Regardless of the lubricant selected, the KAESER SIGMA lubricants will separate readily from water.
If condensate occurs it can easily be removed. Let the compressor sit so that any water can drain
back to the separator tank and separate to the bottom. See chapter 10.14 proper draining procedure.
KAESER has several lubricants available that are specially formulated to match these demands. They
feature excellent lubricity, outstanding demulsibility (ability to separate from water), and long life.
M-SERIES:
■ M-Series SIGMA compressor cooling oils are semi-synthetic lubricants.
■ M-Series SIGMA compressor cooling oils are the highest quality petroleum lubricants. M–460 is
specially blended to provide reliable performance in KAESER screw compressors.
2
Technical Data
2.11 Motors and power
Number: 9_6945 01USE
Service manual Screw compressor
Aircenter SX 3/7.5 SIGMA CONTROL BASIC
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