motor does not perform in accordance with the requirements of the
specifications, changes or corrections shall be made and new complete
witness tests run, at no additional cost to the Government.
2.12.2
Complete Test
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NOTE: For the large motors (1,500 hp and above),
the efficiency is high, i.e. 95 percent at 1/2 to
full load, however, efficiency varies with motor
design. In general, high efficiency motors are not
cost effective in the large size motors covered by
this specification. If other than manufacturer's
standard efficiency is required, the designer should
list those values in paragraph FACTORY TEST.
**************************************************************************
A complete test of a synchronous motor shall including the following:
a.
Resistance of armature and field windings.
b.
Polarity of field coils.
c. High-potential tests of armature and field windings in accordance
with NEMA MG 1 paragraph 21.52.
d.
Air gap measurement.
e.
V-curves (for zero, 1/2, 3/4, and full load).
f. Determination of the subtransient, transient, and synchronous
reactance.
g. Conventional efficiency tests, in accordance with NEMA MG 1
paragraph 21.44. Motor shall meet manufacturer's published efficiency
criteria for 1/2, 3/4, and full rated loads. Calculation of efficiency
shall include [that portion of the thrust bearing loss produced by the
motor itself] [bearing loss due to external thrust load].
h. Tests to determine temperature rise in accordance with NEMA MG 1
paragraph 21.40.
i. Insulation resistance-temperature test, in accordance with IEEE Std
43. Test result values shall be plotted on semilogarithmic graphs, the
insulation resistance values as logarithmic ordinates and the
temperature values as uniform abscissas. Readings shall be taken at
approximately 10 degrees C intervals. Temperature shall be determined
by the resistance method. Also, for comparison purposes, a curve
indicating the safe operating value of insulation resistance shall be
plotted on the same sheet.
j.
Noise level tests in accordance with NEMA MG 1 paragraph 20-50.
k.
Motor balance in accordance with NEMA MG 1 paragraph 20.54.
l.
Conformance test in accordance with NEMA MG 1 paragraph 20.49.
m. Torques. Torque tests shall be performed in accordance with IEEE
Std 115 to demonstrate that the values specified in paragraph
SECTION 16222A
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