factor. Use final sentence of item f. only when the
pump and motor are furnished under the same
procurement.
**************************************************************************
All motors shall have a nonhygroscopic, sealed, fungus-resisting insulation
of a type designed and constructed to withstand severe moisture
conditions, and insofar as practicable, to operate after long periods of
idleness without previous drying out. All windings and connections shall
be of the sealed type as defined in NEMA MG 1 paragraph 1.27.2. Insulated
windings, unless otherwise approved, shall be completely assembled in the
motor core before impregnating with the insulating compound. The compound
shall consist of 100 percent solid resin.
a. Impregnation of the windings with the insulating compound shall be
by vacuum impregnation method followed by baking. The procedure shall
be repeated as often as necessary to fill in and seal over the
interstices of the winding, but in no case shall the number of dips and
bakes be less than two dips and bakes when the vacuum method of
impregnation is used. The completed stator shall be of a type that is
capable of passing the submerged or sprayed water test, as applicable,
required by NEMA MG 1 paragraph 20.49.
b. Random wound coils may be used on motors supplied in NEMA frame
size 445 TP and smaller. The components of the insulation system and
the conductor insulation of the coils shall be Class F insulation with
a 110 percent continuous overload factor as defined in NEMA MG 1
paragraph 1.66. After winding, the completely wound stator shall be
encapsulated with an insulating resin as defined in NEMA MG 1 paragraph
1.27.1.
c. Form wound coils shall be used on motors supplied in NEMA frames
larger than 445 TP. The components of the insulation system and the
coil insulation of the rectangular conductors shall conform to Class F
insulation with a 110 percent continuous overload factor as defined in
NEMA MG 1, paragraph 1.66. The completed stator windings and
connections shall be of the sealed type as defined in NEMA MG 1
paragraph 1.27.2.
d. Insulation to ground shall be processed on the coil. Slot tubes or
cells are not acceptable. The insulation shall be of adequate
thickness and breakdown strength throughout the length of the coil.
Mica shall be used in the slot portion and shall be of adequate
thickness to withstand the dielectric tests specified in paragraph
FACTORY TESTS. Form wound coils shall be of such uniformity that the
stator windings on motors of equal ratings shall be alike, in shape and
size, and be interchangeable.
e. The Contractor shall submit motor design (characteristic) curves or
tabulated data (test or calculated), indicating the speed, power
factor, efficiency, current, and kilowatt input, all plotted or
tabulated against torque or percent load as abscissa. The base value
shall be given whether ANSI or IEEE standard system is used. The
maximum allowable reverse rotation speed for the motor shall also be
provided.
f. The Contractor shall submit [pump and] motor speed-torque curves
for the pump starting operation. The motor speed-torque curves shall
be plotted for the following values of voltage at the motor terminals:
SECTION 16221A
Page 15
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