Torque and Accelerating Time Studies (MTATS), the following data:
a. Complete equivalent circuit data referred to the stator with
friction, windage, and stray load losses.
b. Current, power factor, and torque versus speed (0-100
percent, inclusive, in 1 percent increments up to 95 percent and
in 0.1 percent increments above 95 percent) and load (0-125
percent, inclusive, in 25 percent increments) as a function of
line voltage (from 80 percent to 110 percent, inclusive, in 5
percent increments), for rated and 90 percent of rated voltage at
starter. Only tabulated data will be required.
c.
Load inertia, Wk2 of motor rotating parts, pound-foot2.
[d. Load inertia, Wk2 of pump rotating parts (wet),
pound-foot2.]
PART 2
PRODUCTS
2.1
MOTORS
**************************************************************************
NOTE: For weak source (high thevenin source
impedance), the electric utility shall be contacted
to determine starting restrictions, maximum inrush,
or voltage dip limits. This is especially critical
for motors over 100 hp.
The designer shall then
perform a Motor Torque and Accelerating Time Study
(MTATS) to evaluate the motor starting torque and
voltage dip requirement. The selection of a reduced
voltage starter shall then be based on the electric
utility requirements and the motor pump arrangement.
**************************************************************************
The motors to be supplied under these specifications shall be of the
vertical shaft type as required by the pump manufacturer, normal or low
starting torque, low starting current, squirrel-cage induction type,
designed for full voltage starting, of drip-proof construction, and shall
conform to the applicable requirements of NEMA MG 1, except as hereinafter
specified.
2.1.1
Rating
**************************************************************************
NOTE: NEMA MG 1, Parts 12 and 20, cover medium and
large induction motors, respectively. Any motor
specified by speed and horsepower will be included
in either Part 12 or Part 20. References to both
parts are listed in some cases, as either or both
parts may apply to a particular project.
**************************************************************************
Each motor shall be wound for 3-phase, 60-Hz, alternating current, and for
the respective operating voltage listed below:
PLANT
PUMP
SERVICE
MOTOR OPERATING VOLTAGE
[_____]
[_____]
[_____]
[_____]
SECTION 16221A
Page 9
Previous Page
