When measuring the full current and resistive current of zinc oxide arresters at operating voltage in a substation, a common problem is that readings fluctuate with inter-phase interference, nearby live equipment, and environmental conditions, making it difficult to use a single measurement directly as a basis for judgment. The resistive current itself accounts for a small proportion of the full current, and the on-site electromagnetic environment amplifies its dispersion; if environmental conditions are not recorded, horizontal comparison with historical data is prone to distortion.
The KDX-9100 zinc oxide arrester tester supports measurement of the arrester's full current, resistive current, and their harmonic components at operating voltage, facilitating reference-voltage-related tests in accordance with on-site procedures, with a reference voltage rise rate of 100V/S±. Regarding range issues, the instrument allows the range to be preset and issues an audible prompt for over-range tests during measurement, which can be used for device grouping and inspection discrimination. During testing, ambient temperature and humidity should be recorded simultaneously so that full current and resistive current data obtained on different dates are comparable.
At the application level, it is recommended to use historical data of the same phase as the comparison baseline and to focus on the trends of resistive current and harmonic components rather than single absolute values. When performing grouping inspection on multiple arresters of the same batch, samples deviating from the group level can first be screened out according to the range prompt and then retested for confirmation.
On-site operation also requires attention: test leads should be routed as far as possible from strong electric field areas, and the same wiring position and phase sequence should be maintained for each measurement; temperature, humidity, and range settings should be noted in the test record to facilitate subsequent traceability and horizontal comparison.
