Home >>  Insulator & Cutout >> Composite Insulator

Composite Insulator

Product Description

We offer different types of composite insulators for substations. Contact us for more details about composite insulators such as TDS, application methods, OEM, etc.

We can supply different types of composite silicone insulators to meet customer requirements as well.


A composite insulator, also called a dielectric or nonconductor, is a material that resists the flow of electric current. This type of silicone rubber material is used in parts of electrical equipment intended to support or separate electrical conductors without passing current through itself. The term is also used more specifically to refer to insulating supports that attach electric power transmission wires to utility poles or pylons.

Composite insulators are less costly, lighter in weight, and have excellent hydrophobic capability. This combination makes them ideal for service in polluted areas. However, these materials do not yet have the long-term proven service life of glass and porcelain.


Small size, easy to maintain; Light weight, easy to install; High mechanical strength, not easy to break; Excellent anti-seismic performance, good anti-pollution performance; Fast production cycle, high quality and stability.

Composite Insulator

Insulators are used in electrical equipment to support and separate electrical conductors without allowing current to pass through the insulator. Silicone rubber is the most widely used polymer insulating material for high voltage products. Our composite insulators provide excellent performance in a variety of climates and harsh conditions, including coastal, desert and industrial environments.

Composite insulators with silicone rubber insulation offer unique performance and are installed worldwide. Hitachi Energy offers a wide variety of insulators, which, combined with our flexible production methods, can provide composite insulators to meet your requirements.

Composite insulators are a special type of insulation control that can play an important role in overhead power transmission lines.

Composite insulators are also called synthetic insulators, non-ceramic insulators, polymer insulators, rubber insulators, etc. The main structure is generally composed of umbrella skirt, FRP core rod and end fittings. The edge of the shed skirt is generally made of organic synthetic materials, such as ethylene propylene rubber, high temperature vulcanized silicone rubber, etc.; the FRP core rod is generally reinforced with glass fiber and oxidized resin as the base material; the end fittings are usually carbon steel or carbon structural steel coated with hot zinc aluminum.

Explosion-proof for maximum safety

Non-brittle material to reduce the risk of damage during handling

Leakage current control through hydrophobicity

Excellent insulation for reduced creepage distances

Flashover resistance

Excellent shock resistance for safety and reliability

Light weight for cost savings

Maintenance-free and excellent contamination performance

UV stability

For high voltage applications and substations

Classification of Silicone Rubber Insulators

Composite insulators can be divided into: line composite insulators and power station and power composite insulators. It can also be divided into rod suspension composite insulator, pin composite insulator, cross arm composite insulator, pillar composite insulator, windproof part composite insulator, composite column insulator, etc.

End fitting structure

The structure of composite insulators varies according to the usage characteristics. In addition to meeting the tensile strength, satisfying the requirements, and being reliably connected to the mandrel, the metal tip needs to be designed to meet the special requirements for application under high voltage. Composite insulators are generally made in the form of rods with very small capacitance. As a result, the voltage distribution on the insulator surface is very uneven. The resulting corona is therefore harmful in normal operation and therefore requires the use of voltage equalization measures. In addition, the synthetic insulating material cannot withstand an arc of several tens of kA. In case of a short-circuit fault, it will burn the umbrellas near the wires and towers, so arc pulling is required. At home and abroad, the

The equalizing ring of the composite insulator is an integral part of the composite insulator. Its role is to control the electric field strength inside the insulator, avoid internal partial discharge, reduce the local electric field strength on the outer surface, especially on the surface of the metal connection part, and reduce radio interference. It draws out the industrial frequency arc, avoids burning the insulator surface, minimizes the local electric field strength near the end face, and improves its anti-fouling performance.

Please contact us, we are ready to solve your problem!