Efficiency
________________________________________________________
Nameplate
3600 rpm
1800 rpm
1200 rpm
Horsepower
Nominal Minimum
Nominal Minimum
Nominal Minimum
150
94.1
93.0
95.0
94.1
95.0
94.1
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Motors shall be rated at 460 volts, 3 phase, 60 hertz, and have service
factor of 1.15 for open dripproof enclosures, and a service factor of 1.0
for all other enclosure types. Enclosures shall be fabricated of cast iron
or aluminum. Enclosures for indoor service other than in the lime slurry
preparation area shall be open dripproof, fully guarded. Enclosures for
the lime slurry preparation area, and for outdoor service shall be totally
enclosed nonventilated or totally enclosed fan cooled. Bearings shall be
antifriction type, and shall have an ABMA-L10 rating life of not less than
80,000 hours at rated speed, and under the thrust loadings encountered
within normal operating ranges. The thrust loading corresponding to an
ABMA-L10 rating life of 5,000 hours at rated speed shall not be exceeded
under any operating condition of the motor or the driven equipment.
Bearings shall be insulated when required to prevent bearing or shaft
damage due to stray shaft currents. Each horizontal motor shall be mounted
on a common baseplate with the driven equipment, or shall be furnished with
separate sole plates and subsole plates to permit removal of the motor
without disturbing the alignment of the driven equipment. Furnish space
heaters for motors rated 19 kW 25 horsepower and above. Space heaters
shall be rated 120 volts, single-phase, 60 hertz. The torque
characteristics of each motor at voltages from 90 to 110 percent rated
voltage shall be as required to accelerate the motor and driven equipment
to full speed without damage to the motor or the driven equipment.
Insulation shall be Class B or Class F, with Class B temperature rise in
accordance with NEMA MG 1. The motor "A" weighted sound level shall not
exceed 84 dBA when measured to conform to IEEE Std 85 at a reference
distance of one meter. Motors shall be of special high-efficiency and
high-power factor design including the following design features: Low-loss
lamination steel, increased stator and rotor length, increased winding
cross section, high-efficiency cooling fan design, and optimized slot
configuration and air gap. Information submitted with the compliance
submittals shall include minimum guaranteed efficiency based on tests
performed in accordance with IEEE Std 112, Method B, with accuracy
improvement by segregated loss determination including stray load loss
measurement. Information submitted shall include percent efficiency and
percent power factor at full load, 3/4 load, and 1/2 load. Provide motor
bearing thermocouples and motor winding resistance temperature detectors
(RTDs) for motors 15 kW 20 horsepower and larger. Thermocouples and RTD's
shall be as specified in paragraph entitled "Temperature Monitor."
2.10.3.3
Motors Rated 150 Kilowatt 200 Horsepower and Larger
Motors shall be rated 4,000 volts, 3-phase, 60 hertz, have a service factor
of 1.0 and conform to ANSI C50.41. The torque characteristics of each
motor at voltages from 85 to 110 percent rated voltage shall be as required
to accelerate the motor and driven equipment to full speed without damage
to the motor or the driven equipment. Insulation shall be Class B or Class
F, with Class B temperature rise in accordance with ANSI C50.41. Insulation
systems shall be mica based. Each motor shall be furnished with not less
than two resistance temperature detectors per phase, embedded in the stator
windings. Detectors shall be rated 10 ohms at 25 degrees C as specified in
SECTION 15864N
Page 66
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