Research & Application of ZXBLQ‑II Zinc Oxide Arrester Live Tester

Introduction

Zinc oxide arresters (ZOA) are core overvoltage protection equipment widely deployed in transmission, distribution and substation power systems. Longterm operating stress, ambient moisture ingress and aging of internal varistor chips will gradually degrade arrester insulation performance, which may trigger insulation breakdown, short circuit and even severe grid safety accidents if undetected. Traditional offline powerfailure testing methods require power outage arrangements, bringing economic losses and scheduling difficulties to power grid operation. Therefore, portable highprecision live testers for zinc oxide arresters have become indispensable diagnostic tools for modern conditionbased maintenance of power equipment. This paper systematically introduces the ZXBLQII zinc oxide arrester tester, covering its working principle, core functional design, hardware features and complete technical specifications, to provide technical reference for field test engineers and substation maintenance technicians.

1. Core Functional Principle of ZXBLQII Arrester Tester

The ZXBLQII tester is a dedicated diagnostic instrument designed to evaluate the electrical health state of all voltagegrade zinc oxide arresters, supporting both liveline energized detection and poweroff offline inspection. Its core testing logic relies on separating and analyzing resistive leakage current — the key characteristic parameter reflecting arrester defects. When a zinc oxide arrester operates under nominal system voltage, the total leakage current flowing through it consists of capacitive current and resistive current. Capacitive current stays relatively stable during normal service, while resistive current rises sharply once internal insulation dampening, varistor aging or microcrack defects occur inside the arrester. By extracting resistive current and its harmonic components, field technicians can accurately judge hidden dangerous faults in a timely manner.

The entire measurement workflow of ZXBLQII is fully controlled by a singlechip microcomputer (MCU). It synchronously captures and calculates multiple critical electrical parameters including total leakage current, resistive fundamental & harmonic current, power frequency reference voltage and its harmonics, active power and voltagecurrent phase difference. To eliminate complex electromagnetic interference on site, the instrument integrates digital waveform analysis, Fourier harmonic decomposition and multilevel digital filtering antiinterference algorithms, ensuring consistent, repeatable and highly accurate measurement results under harsh substation electromagnetic environments.

2. Key Technical Features of ZXBLQII Tester

This equipment integrates humanized operation design and advanced measurement hardware, with seven prominent technical advantages oriented to onsite power test scenarios:

Intuitive HumanMachine Interaction Interface The tester is equipped with a largescreen LCD display and full English menu navigation, with simplified operation logic that lowers the learning threshold for field technicians. Operators can complete parameter configuration, realtime data observation and result browsing without complex training.

HighReliability Data Acquisition System Highprecision sampling and signal processing circuits cooperate with advanced Fourier harmonic analysis algorithms to eliminate calculation distortion, greatly improving the credibility of test data for arrester health evaluation.

HighSpeed Magnetically Isolated Digital Sensors Builtin highspeed magnetic isolation digital sensors directly collect voltage and current field signals. The magnetic isolation structure completely isolates highvoltage interference between the measured primary circuit and internal measurement circuit, realizing dual guarantee of data stability and operator personal safety during live testing.

Dual Voltage Synchronous Sampling Modes for Different Site Conditions 

Type II configuration supports wireless synchronous voltage sampling, which avoids long signal wiring and adapts to complex substation layout with scattered arresters;

Type I version adopts electric field induction voltage acquisition, removing the requirement of secondary PT wiring connection, which drastically shortens onsite preparation time and reduces wiring safety risks.

Professional Calibration & Output Functions It supports resistive current fundamental peak value output and crossphase correction functions. Crossphase interference is a common error source in multiphase arrester live detection; the side phase correction module effectively offsets interphase coupling errors and optimizes measurement precision in threephase substation environments.

Integrated Data Storage & OnSite Printing Module A builtin rechargeable lithium battery, realtime calendar clock and miniature thermal printer are fully integrated. The internal memory can store up to 120 groups of complete measurement records, supporting instant printed test reports for archiving and subsequent equipment state tracking.

Portable Integrated Body Design All functional modules are integrated into a compact mainframe, facilitating mobile transportation for patrol inspection of outdoor transmission line arresters and distribution station equipment.

3. Detailed Technical Performance Indicators

All technical indexes of ZXBLQII meet the measurement precision requirements of power industry standards for zinc oxide arrester live detection, with detailed parameters listed as follows:

Full leakage current measuring range: 0~10 mA RMS, applicable for both 50 Hz and 60 Hz power grids, measurement accuracy: ±(reading × 5% + 5 μA);

Resistive fundamental current precision (PT secondary wiring mode without interphase interference): ±(reading × 5% + 5 μA);

Current harmonic component accuracy: ±(reading × 10% + 10 μA);

Reference voltage input range: 25 V ~ 250 V RMS, suitable for test signals with total harmonic distortion below 30% under 50/60 Hz;

Reference voltage measurement accuracy: ±(reading × 5% + 0.5 V);

Voltage harmonic test precision: ±(reading × 10%);

Phase angle measuring range between fundamental current and fundamental voltage: 0° ~ 360°, covering all actual operating phase characteristics of arresters;

Power supply performance: Builtin rechargeable battery supports continuous 6hour field testing; external charging power input is 220 V ± 10% at 50/60 Hz, with a full charging cycle of 5 hours;

Mainframe physical parameters: Outer dimension 325 × 280 × 140 mm, host weight 3.5 kg (excluding test connecting cables);

Adaptable working environment: Operating temperature range -10 ℃ ~ 50 ℃, relative humidity less than 90%, adapting to seasonal outdoor and indoor substation test conditions.

4. OnSite Application Value for Power System Maintenance

Traditional periodic poweroff tests of zinc oxide arresters bring unavoidable grid power cut loss and heavy coordination workload. The ZXBLQII zinc oxide arrester tester solves this pain point by enabling uninterrupted liveline diagnostic testing. For power grid maintenance technicians, its application values are reflected in three aspects: First, realtime hidden fault early warning. By continuously tracking the change trend of resistive leakage current and harmonic content, maintenance staff can capture early insulation dampening and varistor aging defects long before arrester failure, realizing predictive maintenance rather than passive fault disposal. Second, greatly improved testing efficiency. The dual voltage sampling modes eliminate complicated secondary wiring work, while wireless synchronous sampling simplifies multiequipment batch testing in large substations. Builtin storage and printing functions realize onestop data recording and report output. Third, wide scene compatibility. The instrument covers all voltage levels of zinc oxide arresters in transmission, distribution and user substations, and the wide temperature & humidity working range supports yearround patrol testing for both indoor cabinet arresters and outdoor polemounted arresters. The magnetic isolation sensor design also effectively protects testing personnel from electric shock hazards in live operation scenarios.

Conclusion

As power grids develop toward high voltage, large capacity and intelligent condition maintenance, live diagnostic technology for overvoltage protection equipment has become a core technical direction in the power test industry. The ZXBLQII zinc oxide arrester tester combines MCU automatic control, Fourier harmonic analysis and magnetic isolation antiinterference technology, with balanced performance in measurement precision, operation convenience and field safety. Its complete set of testing functions and rich expandable sampling modes can fully satisfy the daily inspection, periodic evaluation and fault diagnosis demands of zinc oxide arresters for power technicians. For power equipment maintenance teams, mastering the working principle, parameter analysis logic and field operation specifications of this tester is essential to improve the overall state monitoring level of substation overvoltage protection equipment and guarantee the safe and stable operation of power grids.

 GDZX is a manufacturer of power detection equipment, offering a diverse range of products with comprehensive models and providing professional technical support. Contact us at +86-27-6552607 or +86-17396104357.Website: http://en.gdzxdl.com/