Composite insulators electrically isolate live parts in power transmission and distribution systems, preventing current leakage to ground. They combine a fiberglass reinforced plastic (FRP) core rod for mechanical strength with a silicone rubber housing and weather sheds for electrical insulation and environmental protection. This construction withstands high-voltage applications, corrosion, and fatigue.
Composite insulators are lightweight, simplifying installation and reducing transportation costs, while their hydrophobicity controls leakage current and prevents flashovers. They resist contamination, require minimal maintenance, and deliver long service life. Voltage ratings range from 11 kV to 1000 kV, with mechanical failing loads from 70 kN to over 500 kN. Advanced manufacturing—including direct injection molding and integral vulcanization—ensures void-free structures and secure connections through crimped end fittings of forged steel or aluminum alloy.
Composite insulators outperform traditional glass and ceramic types, which are brittle and demand frequent inspection. Composite designs provide superior pollution resistance and installation flexibility, performing effectively in urban areas, coastal regions, deserts, and high-altitude locations. They comply with international standards including IEC 61109, IEC, IEEE, and ANSI, with approvals from organizations such as KEMA and State Grid Corporation of China. Selection should consider voltage rating, environmental conditions, tensile strength, creepage distance, and local contamination resistance requirements.
Composite Insulator Manufacturer
Welcome to RaxPower, China’s leading manufacturer of pole line hardware and a specialist in silicone composite insulators. With over 21 years of experience, we provide high-quality, reliable, and cost-effective solutions tailored to the unique demands of power transmission and distribution networks. Our composite insulators ensure electrical isolation and mechanical support in overhead lines, withstanding harsh conditions like pollution, UV radiation, and extreme temperatures, thereby enhancing grid efficiency and safety.
The insulators feature silicone rubber housing made through whole injection molding, offering excellent hydrophobicity, hydrophobicity migration, and soil resistance, which effectively prevent pollution flashovers and reduce maintenance. The core uses corrosive-resistant ECR fiberglass reinforced epoxy resin rods, providing high tensile strength (over 1200 MPa), stress corrosion resistance, and durability. Advanced crimping techniques and multiple sealing systems secure end fittings, ensuring mechanical integrity and long-term reliability.
Our manufacturing processes utilize automatic injection molding and voice-operated displacement crimping machines in our 17,000 square meter facility, supported by in-house R&D and strict quality control, including raw material selection and multi-stage testing. We adhere to ISO 9001 standards, and our products have passed SGS certifications and tests by authoritative institutes, complying with IEC and IEEE requirements.
Contact us now to get the most competitive ex-factory prices.
| Type | Rated Voltage (kV) | Mechanical Failing Load (kN) | Creepage Distance (mm) | Lightning Impulse Withstand Voltage (kV) | Wet Power Frequency Voltage (kV) |
|---|---|---|---|---|---|
| Suspension | 11 | 70 | 300 | 95 | 38 |
| Suspension | 33 | 70 | 580 | 170 | 70 |
| Suspension | 66 | 120 | 1000 | 350 | 140 |
| Suspension | 110 | 120 | 1800 | 650 | 280 |
Frequently Asked Questions (FAQS)
What is a composite insulator?
Composite insulators are engineered from a combination of materials: a core rod made from fiberglass reinforced epoxy resin for mechanical strength, a housing sheath of high-temperature vulcanized silicone rubber for electrical insulation and environmental protection, and metal end fittings for connection. They electrically insulate live parts of electrical systems, prevent current leakage, and withstand environmental conditions like UV radiation, extreme temperatures, and mechanical stress.
What are the main advantages of composite insulators?
Composite insulators offer lightweight design for easier installation and cost savings, high mechanical strength to resist shattering, excellent pollution and contamination resistance, low maintenance requirements, extended creepage distance, high withstand voltage, and durability against cracking and wear. Their silicone rubber housing maintains hydrophobicity and tracking resistance, reducing flashover risk in harsh environments.
In which applications are composite insulators typically used?
Composite insulators are widely used in high-voltage transmission lines to prevent electrical arcing and flashovers, in substations as isolators, bushings, and surge arresters, in electrical equipment like circuit breakers and transformers, in railway electrification overhead catenary systems, in renewable energy projects, and in industrial facilities and distribution lines for reliable insulation and support.
How do composite insulators perform in extreme weather and polluted environments?
Composite insulators are designed to operate effectively in coastal, desert, and industrial environments. They feature UV stability, thermal resistance to both hot and cold climates, and hydrophobicity to control leakage current. Their materials resist environmental stress cracking, salt, dust, and pollution, ensuring long-term reliability under temperature fluctuations, moisture, and mechanical loads with minimal maintenance needed over their service life.
What standards and certifications do your composite insulators comply with?
RaxPower composite insulators adhere to international standards such as IEC, IEEE, and ANSI, and hold certifications like KEMA, Saudi SEC approval, and ISO quality management systems. They undergo rigorous multi-stage testing for electrical, mechanical, and environmental performance by authoritative laboratories to ensure safety, reliability, and compliance with global industry requirements for critical grid applications.
Are your composite insulators suitable for railway electrification?
Yes, our composite insulators are engineered for railway applications, offering high durability to withstand constant vibration and mechanical stress. They comply with relevant railway standards, featuring excellent seismic performance, pollution resistance, and long-term reliability for safe and efficient operation in demanding overhead catenary systems.
How do you maintain consistent quality and competitive pricing for OEM partnerships?
We achieve cost-effectiveness through automated production technologies, such as hot forging and precision machining, which enhance product uniformity and reduce waste. Strict raw material selection and multi-stage quality inspections, including load and gauge tests, ensure consistent performance. This approach allows us to offer competitive pricing while delivering reliable, high-quality components that protect your brand integrity.
What is your capacity for large-scale orders and delivery timelines?
With extensive production facilities spanning 17,000 square meters and advanced automated manufacturing processes, we efficiently handle bulk orders. Our streamlined production cycle and robust logistics ensure timely delivery, supported by a dedicated team that monitors project timelines closely to meet critical deadlines of large-scale infrastructure projects.
Frequently Asked Questions
What is a guy strain insulator used for?
Guy strain insulators are intended for use with down guys or pole-to-pole guys on overhead lines. The insulative rod electrically isolates the guy strand from ground potential, preventing leakage currents to the anchor and providing electrical clearance for maintenance crews and the public during normal operation.
What materials and UV protection are used in guy strain insulators?
They typically feature a fiberglass rod with veil for UV protection, or porcelain. End fittings are made from hot-dip galvanized ductile iron for durability and corrosion resistance. Additional UV protection options include silicone coatings, which protect against ultraviolet rays, acid rain, and harsh environmental conditions.
What strength ratings and end fitting options are available?
Available strength ratings range from 15,000 lb to 80,000 lb, including common ratings of 16,000 lb, 21,000 lb, 30,000 lb, 36,000 lb, and 50,000 lb. End fitting options include clevis, clevis with roller, clevis thimble eye, and clevis eye, designed for consistent high-performance holding strength and compatibility with various hardware.
Are custom lengths available?
Yes, custom lengths are available. Please contact RaxPower for more information on specific requirements and options.
How does RaxPower ensure quality and compliance for critical infrastructure?
RaxPower's guy strain insulators are tested and verified to meet ANSI C29.4 standards, with proof testing and permanent marking to ensure compliance. Multi-stage testing, load testing, and 100% quality checks before packing ensure long-term reliability and consistent performance for grid applications.
Can RaxPower accommodate large-volume orders with customization for EPC projects?
Yes, RaxPower offers tailored solutions including custom lengths and a wide range of end fitting configurations to meet specific project requirements. Our extensive catalog, configurator tools, large warehouse facilities, and efficient production processes enable us to handle bulk orders with flexibility, precision, reliable supply, and competitive wholesale pricing for distributors.
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