For the same arrester, the reference voltage and leakage current measured by different testers often differ. The root cause usually lies in the voltage sampling method and the degree of isolation between high and low voltage. The HZ-9700 zinc oxide arrester tester starts from engineering parameters and makes adjustments targeting these two points.
Compared with some testers using non-isolated architectures, the HZ-9700 adopts low-voltage isolation design in the voltage and current sensors as well as inside the host. The reference voltage measurement error is controlled within ±1% ±2 digits within the rated range, and the leakage current basic error is ±2% ±2 digits within the 0.1mA to 10mA range. The built-in lithium battery supports continuous operation for about 6 hours, adapting to on-site work without an external power supply.
With non-isolated solutions, when taking voltage from a PT, once the secondary side is short-circuited or interference is introduced, measurement may be affected or even operation may be threatened. The HZ-9700 completely isolates the high-voltage side from the host, and only low voltage is used inside the host, reducing the risk caused by wiring errors.
In PT wiring mode, the voltage signal must be taken from a PT that is from the same source and same phase as the arrester, and short circuits on the secondary side must be strictly prevented. When using a current clamp, the jaws should be clean and fully closed, and the direction markings should uniformly face the arrester body. The HZ-9700 provides wiring confirmation prompts in the interface, reducing deviations caused by voltage being taken from a different source or the clamp jaws not being closed.
Suitable for de-energized or live testing of zinc oxide arresters in substations, power plants, and industrial and mining enterprise power distribution systems, in conjunction with regular preventive testing and troubleshooting.
