2.1.9.3
Guide Bearings
Guide bearings shall be of the sleeve or antifriction type of either the
ball or roller type or a combination of sleeve and antifriction bearings.
2.1.9.4
Lubrication
Bearings shall be either oil or grease lubricated and the lubricant used
shall contain a corrosion inhibitor. Type and grade of lubricant used
shall be shown on a special nameplate which shall be attached to the frame
of the motor adjacent to the bearing lubricant filling device. In addition
to the quantity of lubricant required to fill the system initially, spare
lubricant shall be provided in sufficient quantity to purge and refill the
system.
2.1.9.5
Housings
Bearing housings shall be of a design and method of assembly that will
permit ready removal of the bearings, prevent escape of lubricant and
entrance of foreign matter, and protected by the lubricant when the motor
is idle. Except for prelubricated antifriction bearings of an approved
type, suitable means shall be provided to apply and drain the lubricant.
Oil-lubricated bearing housings shall be provided with oil-level indicator
gauges that will be readily visible.
2.1.9.6
Cooling
All bearings shall be self-cooling unless otherwise specifically approved
by the Contracting Officer. If the use of cooling is approved, the means
employed shall, unless otherwise approved by the Contracting Officer,
require no auxiliary pumping equipment; and suitable means shall be
provided to indicate the bearing temperature, actuate an alarm when the
bearing temperature is above normal, and actuate a device to shut down the
motor when the maximum safe operating temperature of the bearing is
reached. Cooling coils shall be of copper tubing and designed for the
operating pressure used to circulate the cooling water. Cooling water
temperature will be [_____] degrees C.
2.1.9.7
Rating
Antifriction bearings shall be rated on the basis of a minimum life factor
of 8,800 hours, based on the life expectancy of 90 percent of the group,
unless otherwise approved by the Contracting Officer.
2.1.9.8
Shaft Currents
Bearings shall be insulated or otherwise protected against the damaging
effects of shaft currents.
2.2
SURGE PROTECTION
2.2.1
Surge Capacitors
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NOTE: To obtain the most reliable protection for
2,300- and 4,000-volt motors, surge capacitors and
arresters, mounted at the motor terminals, should be
specified. In addition, it is recommended that
SECTION 16221A
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