Portable Zinc Oxide Lightning Arrester Characteristic Tester

A: Test data-such as that from a multimeter or test generator-can only provide precise measurements; it cannot indicate whether the device is in good or poor condition. The leakage current of a zinc oxide surge arrester varies depending on its voltage rating. The higher the voltage rating, the greater the leakage current. When analyzing measurement data, you generally examine the fundamental component of the total current, the peak value of the total current, the fundamental component of the resistive current, the peak value of the resistive current, and the phase angle difference.

A:Valve-type surge arresters cannot be tested with this equipment. They contain a component similar to a spark gap; if the applied voltage does not exceed the spark gap voltage, the circuit is effectively open, and the leakage current is 0.

A: This occurs because the three phases of high-voltage lines are relatively close together, and the induced voltages from the other two phases affect the current in the current phase, resulting in a lower reading for Phase A and a higher reading for Phase C. This is a normal physical phenomenon and does not indicate a problem with the testing principle or the tester.