Overview

Surge arresters are the foundation for the insulation coordination of various electrical equipment in the power system (transformers, reactors, capacitors, generators, motors, PTs, CTs, circuit breakers, contactors, etc.). The protective performance of surge arresters determines the internal and external insulation indicators (short-time power frequency withstand voltage, lightning impulse withstand voltage, and switching impulse withstand voltage, etc.) of all electrical equipment in the power system.

Metal oxide surge arresters, commonly known as "zinc oxide surge arresters," are a new generation of surge arresters that were first popularized and promoted internationally by countries such as the United States and Japan in the 1980s. They are the most advanced products among conventional surge arresters. After my country fully introduced this technology in the mid-1980s, and through years of practice and assimilation, the performance of AC surge arresters from various specialized surge arrester manufacturers is now comparable to that of the most advanced products from the United States, Japan, and Western Europe. Products that truly meet all national standards can also meet the requirements of international IEC standards.

The core working element of this product is made of multi-metal oxide powder with zinc oxide as the main component, exhibiting excellent nonlinear volt-ampere characteristics, fast steep wave response, and large current capacity. The gapped product uses a self-blowing gap with a voltage equalization irradiation structure, reducing discharge dispersion and minimizing the impact factor.

The adoption of composite insulation jackets aligns with the international trend towards miniaturization, safety, and maintenance-free operation of power products. Compared to traditional inorganic materials such as ceramics and glass, polymer organic composite materials offer advantages such as small size, light weight, resistance to dirt and cleaning, and explosion and shock resistance.

Model and Meaning

Applications and Implementation Standards

This product is used in AC 220kV and below power generation, transmission, transformation, and distribution systems to limit the amplitude of lightning strikes and internal system switching overvoltages to specified levels. It is a fundamental piece of equipment for the insulation coordination of the entire system. However, this product cannot be used to limit resonant overvoltages; harmonic suppression in such systems requires other methods.

The model designation of this product shall be in accordance with the provisions of JB/T8459-1996 "Method for Compiling Product Model Designations for Surge Arresters". Gapless products shall comply with GB11032-2000 "AC Gapless Metal Oxide Surge Arresters" standard; gapped products shall comply with JB/T9672-2005 "Metal Oxide Surge Arresters with Series Gap" standard. For important parameters and configurations not explicitly defined in the above standards, modifications shall be made in accordance with the requirements of DL/T620-1997 "Overvoltage Protection and Insulation Coordination of AC Electrical Installations".

Environmental conditions for use

The normal operating conditions for standard products are as follows:

Ambient temperature: not higher than +40℃, not lower than -40℃

Altitude: Not exceeding 3000m;

Power supply frequency: 50±2HZ; 60±2HZ

Maximum wind speed: 35 m/s;

No-cleaning conditions: Areas with moderate or less soiling;

For gapless products, the long-term applied power frequency voltage must not exceed the continuous operating voltage of the surge arrester;

For products with gaps, the short-term power frequency voltage rise at the installation point must not exceed the rated voltage of the surge arrester.

For long-term use under the following abnormal conditions, surge arresters need to be specially manufactured, and this should be specified when ordering:

Temperature or altitude exceeding the standard (high altitude, tropical, frigid zones, use in fully enclosed cabinets, proximity to electric stoves, etc.);

The operating environment contains severe moisture or corrosive gas impurities (on water, in salt fields, in chemical plants, etc.);

Strong ultraviolet radiation (high-altitude areas, arid regions with strong sunlight, etc.);

Extremely polluted areas (mining faces, construction site faces, etc.).

Technical Specifications (Typical for Regular Products)

The following is a typical parameter table for conventional surge arresters, arranged from low to high voltage level for easy user reference.

Note:

Each national standard model can be derived into several product models. Due to space limitations, they are not listed here. If users have any questions about the models, they can directly consult our company's technical department.

In the "System Nominal Voltage" column, data marked with an asterisk (*) represents the rated voltage of the motor corresponding to the surge arrester for motor protection; in the "Power Frequency Discharge Voltage" column, data marked with an asterisk (*) represents the effective value of the power frequency withstand voltage for high-voltage surge arresters above 110kV.

Due to the wide range of applications and voltage levels, the surge current value corresponding to the 30/60 switching impulse residual voltage of the surge arrester is not specifically specified;

Most products can be equipped with accessories such as disconnectors and counters. Add "L" to the model number if using a disconnector, and add "J" to the end of the model number if using a counter.