Higher
Increased efficiency,
higher
power factor
Higher
speeds -
Increased efficiency,
higher
power factor
For motors above 100 hp, efficiency and power factor
may not be a consideration since most motors of this
size have a rated efficiency of around 90 percent
and a power factor of greater than 0.8. When this
is the case, delete power factor efficiency
requirements from paragraph MOTORS, and the
certification requirement in paragraph SUBMITTALS.
The designer should consult manufacturer's
literature and individual applications for
efficiencies and power factor to specify. The
designer should also weigh the cost of a more
efficient motor vs a larger motor with increased
efficiency due to size. Generic motor data are
available which may be used if manufacturer's data
are not available.
**************************************************************************
The power factor and efficiency at full load, 3/4 full load, and 1/2 full
load shall be not less than [_____], [_____], [_____] and [_____], [_____],
[_____], respectively. Motors will be rejected if factory tests specified
in paragraph FACTORY TESTS do not demonstrate that these values will be met
or exceeded.
2.1.3
Frames and Brackets
Frames and end brackets shall be of cast iron, cast steel, or welded steel.
The mounting ring, unless otherwise approved, shall be built integral with
the frame or lower end bracket and arranged for direct mounting on the
pump, or station floor, or as required by the installation conditions.
Treatment against corrosion shall be as specified in paragraph GENERAL
REQUIREMENTS.
2.1.3.1
Stator Frame
The stator frame shall be rigid and sufficiently strong to support the
weight of the upper bearing bracket load, the weight of the stator core and
windings, and to sustain the operating torques without perceptible
distortion. The stator frame, if not direct mounted on the pump, shall be
supported on a motor base or drive pedestal which in turn will be supported
on sole plates or other suitable structure installed in the concrete
foundation constructed as part of the pumping station structure. The motor
base or drive pedestal shall be provided with bolts and dowels for
fastening to the sole plates or supporting structure for preserving the
alignment.
2.1.3.2
Supporting Bracket
The upper bracket supporting the thrust bearing and upper guide bearings
shall have sufficient strength and rigidity to support the weight of the
entire rotating element of the motor, together with the pump impeller and
shaft, and the hydraulic thrust of the pump impeller.
SECTION 16221A
Page 13
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