W912P5-16-R-0002TSpecsAm7Pages.pdf

Unit 4 Rehabilitation Old Hickory Powerhouse W912P5-16-R-0002 Amendment No. 0007 Sumner County, Tennessee shall be 40 °C and 155 °C. An average heating and cooling rate of 2.5 °C ± 1°C per minute shall be used. Temperature controls shall be in accordance with the standard. Coil surface temperatures shall be measured. Perform the diagnostic tests listed in IEEE 1310 paragraphs 7.1, 7.2, 7.4, and 7.5 prior to and at the completion of the thermal cycling test. Perform the proof tests of IEEE 1310 paragraph 8.1 and the voltage endurance test of paragraph 8.2 utilizing IEEE 1043. The test coils shall be deemed as having passed the thermal cycling test if they can pass both the proof tests of IEEE 1310 paragraph 8.1 and the voltage endurance test of IEEE 1310 paragraph 8.2. Dissection shall be performed on the two test coils and the temperature control coil. A thermal cycling test report shall be prepared in accordance with paragraph 9 of the standard and shall be submitted for approval. Report photographs shall also be provided in electronic format. Production of new stator coils shall not begin until the test report has been approved.

3.5 COIL TESTS AT FACTORY

The Contractor shall perform the following tests on each coil. The Contractor shall submit for approval the factory test methods. If more than 1% of the coils fail, production shall be stopped, the Government shall be notified, and the cause for failure shall be established and corrected. At the completion of the tests, the Contractor shall submit for approval the factory coil test report for each test. Certified test results of all factory tests shall be submitted. Approval shall be obtained prior to shipment of any coils from the factory.

a. Strand Continuity and Strand Insulation. The continuity of each strand shall be established by a suitable test prior to checking the strand insulation. The insulation integrity between all strands within a conductor shall be tested by applying a minimum of 120 VAC rms between each strand and all other strands of the conductor.

b. Turn Insulation Dielectric Test. The turn-to-turn insulation of each stator coil shall be tested by a high frequency turn-to-turn dielectric test (surge test) to 39.4 kV with a front rise time of 0.1 microseconds, per IEEE 522.

c. Ground Insulation Dielectric Test. The ground insulation of each stator coil shall be subjected to a withstand test of 40 kV AC for one minute. Visible corona detected under typical factory lighting of 100 ft-c shall be grounds for rejection.

d. Power-Factor Tip-Up Tests. Power-factor measurements shall be made on each coil in accordance with IEEE 286. Tests shall be made at 20 and 100 percent rated (line-to-ground) voltage. If the numerical difference between the two power factor measurements is greater than

0.9 percent, the coil will be rejected.

e. Dissipation Factor Test. In addition to the power-factor tip-up test, every tenth coil produced shall be given a dissipation factor test. This test shall consist of subjecting the coil, using the same setup as the tip-up test, to AC voltages of 20 through 200 percent of rated (line-to-ground) voltage. To compensate for occasional measurement anomalies, the averaging of a single step value not meeting the specified criteria with the next highest step will be permitted.

Should the two steps have different acceptance criteria, these also may be averaged. For each coil that fails the dissipation factor test, SECTION 48 13 16.00 Page 23

Unit 4 Rehabilitation Old Hickory Powerhouse W912P5-16-R-0002 Amendment No. 0007 Sumner County, Tennessee four additional coils shall be tested. The dissipation factor shall be measured as a function of voltage at each 20 percent interval of rated voltage, i.e., 20, 40, 60, 80, 100, 120, 140, 160, 180, and 200 percent. Dissipation factors shall not exceed the values given in the following table:

For each 20% The dissipation factor interval shall not increase by between: and: more than:

20% 60% 0.0015 60% 120% 0.003 120% 200% 0.004

f. Stator Coil Dimension Check. The Contractor shall fabricate a stator core segment for use in verifying dimensional compatibility of the new stator coils with the existing stator core. The stator core segment shall include critical features such as ends of laminated iron, clamping fingers, clamping plates, and surge rings. The core segment shall be sufficient in size to test the fit of a minimum of ten coils at a time.

3.6 COIL ACCEPTANCE CRITERIA

Coils meeting this acceptance criteria will be accepted for delivery to the job site. The acceptance criteria consists of Government approval for the following items:

a. Prototype coil test report;

b. Production run coil test report;

C. Thermal cycling test report; and

d. Factory coil test report.

In addition to Government approval of the above items, coil dissection slices from the accelerated life tests must meet the void free requirement described in the Resin Impregnation and Curing paragraph. The void free requirement does not apply to coils that have undergone the thermal cycling test.

3.7 SPRING TYPE FILLER MATERIAL TEST

Representative samples of the spring material shall be subjected to the tests specified in this paragraph. Failure to pass these tests shall require the spring material to be redesigned and retested. The spring height is defined as the total height of the spring minus the material thickness (that is, the distance that the height of the spring can be compressed). Samples of each size to be used in the generator shall be tested. The wedging deflection characteristics shall be submitted for approval. The force required for an 80 percent reduction in spring height shall be at least 110 psi. After this measurement, the test samples shall be conditioned by compressing them 100 percent (completely flat) between steel plates. They shall be kept in this position at 120 degrees C for 168 hours. After conditioning, the force required for an 80 percent reduction in spring height shall be at least 65 percent of the pre-conditioning force. The uncompressed spring height shall have shrunk less than 20 percent. The Contractor shall submit spring test report or catalog cut at

SECTION 48 13 16.00 Page 24