CSA C88.1-96 pdf free download

CSA C88.1-96 pdf free download.Power transformer and reactor bushings.
8.2 Full-Wave Lightning Impulse Withstand Voltage
A standard 1.2/50 microsecond wave shall be used. Fifteen positive and fifteen negative impulses
having crest values of the specified levels shall be applied to the bushing. If no more than two
flashovers occur per series of fifteen tests, the bushing shall have passed the test.
8.3 Chopped-Wave Lightning Impulse Withstand Voltage
The applied voltage shall have a crest value and time to flashover in accordance with Table 1, Columns
9 and 10. A minimum of three impulses of negative polarity shall be applied to the bushing. If
subsequent tests indicate permanent damage, or if flashover occurs, the bushing shall be considered to
have failed.
8.4 Positive Wet Switching Impulse Withstand Voltage
The positive wet switching impulse withstand voltage test shall be conducted with artificial rain in accordance with Clause 7.3.3. The artificial rain shall impinge on the bushing for at least 15 minutes immediately before the test voltage Is applied and shall continue during the test. Fifteen positive switching impulse waves with crest values in accordance with Column 7 of Table 1 shaLl be used. The front of wave shall be 200—300 microseconds and the total duration shall be 1,000-4,000 microseconds. The voltage shall be held at 90 per cent of its crest value for at least 200 microseconds. If no more than two flashovers occur, the bushing shall have passed the test. Alternately, statistical evaluation of test data must estabish the probability that the withstand value is 90 per cent or greater of the value in Column 7 of Table 1.
8.5 Wet, One-Minute Low-Frequency Withstand Voltage
The tests shall be performed on the bushing in accordance with Column 6 of Table 1. The test shall be conducted with artificial rain In accordance with Clause 7.3.3. The artificial rain shall impinge on the bushing for at least 15 minutes immediately before the test voltage is applied and shall continue during the test.
If the bushing withstands the specified test voltage for the specified time, it shall be considered as having passed the test. If a single flashover occurs, the test may be repeated. If the repeat test also results in flashover, the bushing shall be considered to have failed.
8.6 One-Hour Low-Frequency Withstand Test with Partial Discharge Measurement
This test may be performed at any frequency between SO and 300 Hz. Apply a voltage equal to 1.7 times the maximum design voltage to ground for the bushing as given in Column 3 of Table 1. Maintain the voltage for a period of 1 mm. Reduce the voltage to 1.5 times and maintain for 1 h. To pass the test, the bushing shall meet the following requirements:
(a) The capacitance, when measured following the test, shall not deviate by more than the limits specified in Table 2.CSA C88.1-96 pdf free download.