(1) Before the test, the test voltage of the test object should be understood, as well as other test items and previous test results. If the test object has defects or abnormalities, the AC withstand voltage test should be conducted after they are eliminated.
(2) The test site should be enclosed with barriers or ropes, signboards should be hung, and dedicated personnel should be assigned for supervision.
(3) Before the test, the surface of the test object should be wiped clean, and the shell and non-tested windings of the test object should be reliably grounded. If the test object is newly filled with oil, the oil should be allowed to stand for a certain period before applying voltage according to the "Regulations". For oil-filled power equipment of 110KV and below, the standing time after filling with oil should be no less than 24 hours; for oil-filled power equipment of 220KV and 330KV, the standing time should be no less than 48 hours.
(4) After connecting the test wiring, it should be checked by experienced personnel to confirm correctness before applying voltage.
(5) Before applying voltage, first check whether the voltage regulator is at zero position. Only when the regulator is at zero can voltage be applied, and the voltage increase should be announced verbally.
(6) During the voltage increase process, not only the voltmeter changes should be monitored, but also the ammeter changes. The cable identifier is a miniaturized portable, compact instrument, housed in an aluminum alloy box, consisting of a signal generator, a receiver with a sensor, and connecting cables. As well as the current changes of the test object. The voltage should be increased uniformly, not too fast. When the specified test voltage is reached, start timing. After the time is up, slowly and uniformly reduce the voltage. It is absolutely not allowed to switch off the power switch without first reducing the voltage.
(7) If during the test the meter needle swings or the test object has abnormal sounds, smoke, etc., the voltage should be immediately reduced, the power switched off, and after hanging a grounding wire on the high-voltage side, investigate the cause.
(8) The insulation resistance of the test object should be measured before and after the AC withstand voltage test.
