(1) Air Compressor
(a) Check the oil level of the crankcase weekly and replenish if necessary. Change oil at least every
500 hours of actual operation. When compressor is installed in a heated room where temperature is above freezing, use
oil, lubricating, engine crankcase, OE-30; when installed in unheated room where temperature is below freezing, use oil,
lubricating, engine crankcase, "OEA".
(b) Clean valves are essential. Inspect and clean valves at least once a year or more often if operating
conditions are severe. Make certain valves are thoroughly dry before replacing.
(c) Remove filter element of air intake filter at least once a month and clean with a blast of compressed
air. If kerosene is used for cleaning the air intake filter, make certain filter is thoroughly dry before replacing; otherwise it
might cause an explosion when air compressor is operated.
(d) Major repairs of the compressor are beyond the scope of organization maintenance and require
replacement of the unit or repair by level specification in maintenance allocation chart.
(2) Electric Motor.
(a) If motor is a sleeve-bearing motor, oil at least every 3 months with oil, lubricating "OEA". Do not use
an excessive amount of oil, as the excess oil is likely to work out on the commutator. If motor is a ball bearing motor,
repack once a year using a grease of about the same consistency as, or slightly stiffer than, Vaseline.
(b) Never oil the commutator; keep it dry and clean.
(c) Periodically blow off the motor windings with a jet of compressed air to prevent an accumulation of
(d) Adjust belt tension, when necessary, by sliding motor along its base and tightening in proper position.
2-27. CENTRIFUGE AND CHANNEL POINT APPARATUS CABINET.
a. Component Parts. The centrifuge and channel point apparatus cabinet (fig. 2-27) consists of three
compartments: the centrifuge compartment, which houses the centrifuge and contains a unit of the cloud- and pour-point
apparatus; the channel point apparatus compartment, which contains the channel point apparatus; and the refrigeration
compartment, which contains the compressors, controls, and blowers for the channel point apparatus. The refrigeration
compartment is located in the lower left portion of the cabinet beneath the centrifuge compartment. Openings in the top
of the cabinet are equipped with hinged covers to provide access to the centrifuge and channel point apparatus.
Change 1 2-48