IEEE Std C37.09 pdf free download

IEEE Std C37.09 pdf free download.AC High-Voltage Circuit Breakers with Rated Maximum Voltage Above 1000V.
4.8.4.4 Test duty TlOOa
(‘hange the first paragraph as follows:
Test duty TlOOa in Tablel consists of a minimum of three opening operations made not more than 15 mm apart at IOO°/o of the rated short-circuit breaking current and power frequency recovery voltages as specified in Table I and 4.8.2.4. If additional tests are required to meet the required asymmetry criteria regarding the peak and duration of the last major loop and the related arcing conditions given in 4.8.2.3.30 4.8.2.3.3 and 4.8.2.3.4 for three-phase tests and in 4.8.2.3.5 for single-phase tests in substitution for three- phase tests;, These these tests may be performed at any convenient interval.
4.8.5.4.3 Condition check after meeting service capability tests
(‘hange the first paragraph as follows:
A test circuit breaker insulation condition check eati shall be performed after current accumulation duty specified in the service capability duty requirements of’ IEEE Std C37.04. The voltage withstand test can be performed by direct method in the high-voltage laboratory or indirect method using synthetic circuit in the high-power laboratory as listed as follows. The direct method is preferred if the high-voltage laboratory is close to the high power laboratory and does not require recovery of used SF6 gas from the short-circuit test to empty bottles for shipment to the high-voltage laboratory:
a) For circuit breakers rated <72.5 kV:
change item b.) to ,,,aiii text under item a):
b A one-minute power frequency withstand tests at 80% of the original rated withstand value.
I) If the test is done with the direct test method, a lightning impulse test with both polarities having a peak value equal to 80% of the rated lightning withstand voltage should be applied. The circuit breaker is to be tested with five impulse voltages and no disruptive discharge is allowed.
2) If the test is done with the synthetic test method, impulse waveforms with both polarities similar to that of’ the applicable rated TRV as used in test duty TlO with a peak voltage equal to 60% of the corresponding rated lightning impulse should be applied. The circuit breaker is to be tested with five impulse voltages and no disruptive discharge is allowed.
c) 4) For circuit breakers rated ?362 kV:
1) If the test is done with the direct test method, a switching impulse test with both polarities having a peak value equal to 80% of the rated switching withstand voltage should be applied. The circuit breaker is to be tested with live impulse voltages and no disruptive discharge is allowed.
2) If the test is done with the synthetic test method, impulse waveforms with both polarities similar to that of the applicable rated TRV as used in test duty TlO with a peak voltage equal to 80% of the corresponding rated switching impulse should be applied. The circuit breaker is to be tested with five impulse voltages and no disruptive discharge is allowed.
4.10.4 Grounding of the supply circuit
Change item a) as follows:
a) For capacitor bank current switching tests, the neutral of the supply circuit shall be grounded. For capacitor banks with grounded neutral, the zero-sequence impedance shall be nt less than three times the positive sequence impedance. For isolated neutral capacitor banks, this ratio is not relevant.IEEE Std C37.09 pdf download.