ZD1 type lightning arrester live measuring instrumentDetailed product description：

The ZD1 lightning arrester live measuring instrument can measure the resistive current and full current of three-phase lightning arresters while live without taking signals from PT. The entire measurement process is convenient, fast, and accurate. The measurement results can be used as a criterion for whether the lightning arrester is abnormal.

Product Introduction
Metal oxide arrester (MOA) has been widely used in power systems. In order to ensure its safe and reliable operation, it is necessary to regularly monitor the changes in its leakage current and resistive current. The diagnosis of early MOA faults is most sensitive in detecting resistive current. Therefore, manufacturers have launched various instruments for measuring resistive current.
The measurement of MOA resistive current with electricity is classified based on measurement principles, and commonly used methods include compensation method combined with phase shifting method, which can accurately measure MOA resistive current and its fundamental value. However, this method requires voltage signals to be taken from the PT secondary side, making the measurement very inconvenient. The harmonic method is relatively convenient for measurement, but it cannot measure the fundamental value of resistive current, which is the most critical value for determining MOA faults.

The ZD1 lightning arrester live measurement instrument adopts the latest measurement method for measurement, without the need to take voltage signals from PT. It can simultaneously measure the full current of three-phase MOA and the resistive component containing the fundamental value in a short time. It is suitable for lightning arrester groups composed of three-phase MOA, and MOA is grounded through an impedance counter; Not suitable for MOA with only one phase installed and the base directly grounded in a three-phase system.
This instrument is small in size and easy to carry. It has a printer and rechargeable battery inside, and can work without an external power source. The measurement results are directly output by the printer, making it convenient for users to organize.

Main Features
① Easy to operate and safe. During testing, there is no need to work on the primary side of the distribution network, only signals are introduced through the PT opening triangle, thus avoiding the possibility of misoperation caused by contact with the primary circuit and the danger of explosion caused by external capacitors used for switching tests. The entire measurement work can be completed within one minute, which is very safe and convenient.
② No special safety measures are required. Due to the weak measurement signal injected from the PT opening triangle, it will not have any impact on the relay protection and PT itself. The output terminal of this tester can withstand an AC voltage of 100V. If there is a single-phase grounding fault in the system during measurement, it will not damage the PT and tester, so no special safety measures are required.
③ The instrument has a small volume, light weight, and is easy to carry.
④ Strong anti-interference ability. By using a different frequency test signal, the 50Hz power frequency interference signal is avoided, and the test results are accurate, stable, and reliable.