Views: 0 Author: Site Editor Publish Time: 2026-06-04 Origin: Site
Power distribution networks are exposed to many types of voltage stress. Lightning strikes, switching operations, and transient overvoltages may damage transformers, switchgear, cables, and other key equipment if proper protection is not installed.
A surge arrester is designed to limit overvoltage and protect electrical equipment from insulation damage. In medium-voltage distribution systems, surge arresters are widely used in substations, transformer stations, overhead lines, cable terminations, and outdoor switching points.
DGG Power provides metal-oxide surge arresters for medium-voltage power distribution applications, supporting utilities, EPC contractors, industrial users, and distribution network operators with practical overvoltage protection solutions.
Product category: Metal-oxide surge arrester / gapless surge arrester
Application system: Medium-voltage distribution networks
Typical applications: Transformer protection, substation protection, overhead line protection, cable terminal protection, and outdoor switchgear protection
Product types shown: Composite-housed surge arresters, porcelain or polymer-type structures, distribution arresters, and products used together with fuse cutouts
Test evidence: Selected DGG Power 10kV AC gapless metal-oxide surge arresters have completed type testing
Customer value: Overvoltage limitation, insulation protection, improved equipment reliability, and reduced risk of power system failure
What Is a Surge Arrester?
A surge arrester is a protective device used to limit transient overvoltage in electrical systems. When the system voltage remains within normal operating range, the arrester stays in a high-resistance state. When an overvoltage occurs, it provides a discharge path to release surge energy and limit the voltage level applied to protected equipment.
In medium-voltage networks, surge arresters are commonly installed near transformers, switchgear, cable terminals, and overhead line equipment to protect insulation from lightning impulse and switching overvoltage.
Medium-voltage equipment is designed with a certain insulation level. However, lightning strikes or switching events may create voltage peaks far above normal operating voltage.
Without proper surge protection, overvoltage may cause:
Transformer insulation damage
Switchgear failure
Cable terminal breakdown
Reduced service life of electrical equipment
Unexpected outage or maintenance cost
By limiting overvoltage, surge arresters help protect equipment and improve the reliability of the entire distribution system.
Distribution transformers are commonly exposed to lightning and switching surges, especially in overhead line systems. Installing surge arresters near the transformer high-voltage side helps reduce insulation stress and supports long-term transformer operation.
Overhead distribution lines are more likely to be affected by lightning activity. Surge arresters can be installed along key line sections or at switching points to reduce the impact of transient overvoltage.
In substations, surge arresters help protect circuit breakers, disconnectors, instrument transformers, busbars, and other primary equipment from overvoltage damage.
Cable terminations and transition points between overhead lines and cables are sensitive locations in distribution networks. Surge arresters help improve protection coordination at these points.
In some outdoor distribution systems, surge arresters are installed together with dropout fuses or fuse cutouts. This combination is commonly used for transformer protection and overhead line protection.
The product images show different structures and designs, including compact distribution arresters, composite-housed arresters, and arresters used together with outdoor protection devices.
These different designs can be selected based on:
Rated voltage and system voltage
Installation method
Outdoor or indoor application
Creepage distance requirements
Environmental conditions
Project specification and protection coordination
For EPC contractors and power utilities, correct arrester selection should be based on the actual system voltage, insulation level, grounding method, and installation environment.
One of the product images shows a test report for a 10kV AC gapless metal-oxide surge arrester. The report identifies the sample as a 10kV AC gapless metal-oxide surge arrester and indicates that the test category is type test.
For customers, type testing is an important part of product verification. It helps confirm that the arrester design has been evaluated according to defined test requirements and supports confidence in product quality.
DGG Power can provide relevant product documents according to project requirements, including technical specifications, test information, and product selection support.
When selecting a surge arrester for a medium-voltage distribution project, customers usually need to consider several key factors:
System rated voltage
Continuous operating voltage
Nominal discharge current
Lightning impulse protection level
Creepage distance requirement
Installation location
Outdoor environmental conditions
Coordination with transformers, cables, switchgear, and fuse cutouts
A suitable surge arrester should match both the electrical system requirements and the actual site conditions. If the arrester is not properly selected, the protection effect may be reduced.
DGG Power supplies surge arresters for medium-voltage distribution systems, including products suitable for transformer protection, overhead line protection, substation applications, and outdoor power equipment protection.
Our product support focuses on:
Practical product selection
Clear technical documentation
Different structure options
Coordination with distribution equipment
Project-based supply and support
For customers working on distribution network upgrades, transformer stations, industrial power systems, or overhead line protection projects, DGG Power can provide suitable surge arrester solutions according to voltage level, installation method, and project requirements.
What is the function of a surge arrester?
A surge arrester limits transient overvoltage and protects electrical equipment such as transformers, switchgear, cables, and overhead line devices from insulation damage.
Surge arresters are commonly installed near transformers, switchgear, cable terminals, overhead line sections, substations, and outdoor switching points.
A metal-oxide surge arrester uses metal-oxide varistor elements to limit overvoltage. It is widely used in medium-voltage and high-voltage power systems because of its nonlinear voltage-current characteristics.
Type testing helps verify that the arrester design meets defined technical requirements. It provides supporting evidence for product performance and quality control.
Selection should consider system voltage, continuous operating voltage, discharge current, protection level, creepage distance, installation environment, and coordination with other equipment.
Surge arresters are essential protective devices in medium-voltage distribution networks. They help limit overvoltage, protect equipment insulation, and improve system reliability.
From transformer protection to overhead line and substation applications, selecting the right surge arrester is important for long-term power system stability.
Looking for surge arresters for transformer protection, overhead line protection, or substation projects? Contact DGG Power to discuss your voltage level, installation method, protection requirements, and project specifications.
