Product Center

Home / Product Category / Insulator / Composite Insulators / Composite Strain Insulator

Composite Strain Insulator

Composite Strain Insulator is a composite suspension and tension insulator designed to keep an energized conductor mechanically secure while electrically isolating it from towers, poles, or other support structures; in IEC terms, it is used in structural support applications such as guy or span wires to prevent leakage current, and IEC 61109 covers composite suspension and tension insulators for AC systems above 1,000 V. Built with a fiberglass core, silicone rubber housing, and metal end fittings, it is widely used in overhead transmission, utility networks, and railway electrification because it offers high mechanical strength, low weight, strong outdoor performance, and excellent resistance to pollution and moisture. It is typically selected together with accessories like arcing horns and corona rings to control electric field stress and improve electrical coordination, making it a critical component for safe and reliable line operation in demanding environments.

Quantity:
Availability:





Inquire Add to Basket

Product Accessories

Arcing horns are commonly used on the live end of strain strings to guide arc energy away from the insulator body during switching or lightning events.

Corona rings are used on higher-voltage strings to smooth the electric field and reduce corona stress near fittings and terminals.

Extension links and coupling hardware are used to achieve the required installation length and to match tower geometry, conductor position, and string layout.

Yoke plates, clevis-eye fittings, and socket-type end fittings are used to connect the insulator string to the structure and to the conductor assembly.

Protective fittings packages can combine corona protection and arcing protection in one string arrangement where the project calls for it.

Get a Quote

Product Specifications

Product type

Composite suspension and tension insulator for overhead lines.

Standard basis

IEC 61109 for composite suspension and tension insulators.

Application definition

strain insulator used in a guy or span wire to isolate the support.

Core material

fiberglass insulating core / GFRP core.

Housing material

polymeric housing, typically silicone rubber.

End fittings

metallic end fittings transferring mechanical load to the core.

Voltage range

published composite insulator systems extend from 1.5 kV to 1000 kV depending on application.

Mechanical load classes

published project and utility references include 120 kN, 150 kN, 300 kN, and 600 kN classes.

Installation position

tension / strain position; some railway references also use vertical installation for feeder support.

Protective fittings compatibility

arcing horns and corona rings can be integrated into the string design.

Product Applications

Economy is more affordable

where the insulator is used in the strain position for anchoring and line support.

25 kV single-phase railway overhead traction lines
where conductor tension must be held securely at tower or station entrances.

Transmission-line dead-ends and terminal anchoring points
where the strain insulator prevents leakage current through the support wire.

Guy-wire electrical isolation on poles and structures
where silicone composite housing and protective fittings are used to improve field performance.

High-voltage line suspension and tension strings in polluted or wet corridors

Product Advantages

High mechanical strength with low weight

Composite strain strings are much lighter than porcelain alternatives, which makes handling and installation easier on site.

Strong outdoor performance in harsh environments

Silicone housing and hydrophobic surface behavior help the insulator perform well in wet, contaminated, or heavy-weather conditions.

Flexible engineering for different projects

The same product family can be adapted with different load classes, fitting styles, and protective accessories to suit utility, railway, and transmission requirements.

WellDone Composite Strain Insulator Plan Drawing

FAQ

What is a Composite Strain Insulator used for?

It is used to hold an energized conductor under tension while keeping it electrically isolated from the supporting structure.
Where is it commonly installed?

It is commonly used on railway overhead lines, transmission dead-ends, and guy-wire support points.
Why choose a composite design?

It is lightweight, strong, and performs well in wet, polluted, and harsh outdoor environments.