We know that under the excitation of sinusoidal voltage, the leakage current of the zinc oxide arrester is composed of capacitive current and resistive current, and the composite waveform is shown in Figure 11. In the full current waveform, the peak value of the first wave peak should be basically the same as the peak value of the fundamental wave current, and the moment of its peak value shifts to the right as the equivalent resistance value of the arrester becomes smaller. The peak value of the second wave crest appears basically at the moment when the voltage peak appears, at which time the capacitive current is basically zero. We only need to try to measure the peak value of the first wave peak, which is the peak value of the fundamental wave current (when the resistive current is not very large, that is, the peak value of the full current), try to measure the peak value of the second wave peak, namely The measurement of the peak value of the resistive current can be realized. The time difference between the first wave crest and the second wave crest is measured, and the value of φ can be obtained.

Before the zinc oxide arrester is officially measured, please turn on the power and warm up the instrument for 5 minutes to make the measurement data more accurate. When taking the reference voltage from the PT secondary, carefully check the wiring to avoid the PT secondary short circuit. Do not connect the voltage signal input line and the current signal input line wrongly. If the current signal input line is connected to the PT secondary side or the measuring end of the test transformer, the instrument may be burnt. 4. In the case of input voltage and input current, do not plug or unplug the measuring line to avoid burning the instrument.

After the instrument is damaged, please stop using it immediately and notify the company, do not open the box and repair it yourself. When the instrument does not work normally, please first check whether the power fuse is blown. When there is no input voltage, check whether the fuse at the front of the test line is blown, and the experiment can be continued after replacing the fuse with the same model. If the problem is more complicated, please contact our company. This instrument should not be placed in a humid and high temperature environment.