Distribution Deadend Insulators – DS-M Series

Distribution Deadend Insulators – DS-M Series

The DS-M Series distribution deadend insulators are manufactured using a conventional silicone rubber housing, formed by injection molding and securely bonded to a high-strength fiberglass core. The voltage range covers 15 kV to 46 kV, and the standard end fitting configuration is Clevis-Tongue connection.

Applications:
These deadend insulators are designed to support conductors under tension or suspension conditions. They are typically installed with one end fixed to a pole, cross arm, or guy wire, ensuring reliable mechanical strength and electrical insulation performance.

DS-15  DS-28  DS-35

Customize the product according to the customer's requirements

Product drawing

Basic feature

Item	Mechanical Load	Rated Voltage	Main difference
DS-15	70kN	15kV	Short creepage distance
DS-28	70kN	28kV	Medium creepage distance
DS-35	70kN	35kV	Maximum creepage distance

Applications:

10kV–15kV power distribution lines

Rural power grids

Urban low-voltage power distribution

Features:
Short creepage distance

Smaller structural size

Lower cost

Applications:
24kV / 27kV / 28kV systems
Lines below 33kV
Medium-voltage distribution networks
Features: Increased creepage distance
Larger insulation length

Applications:

35kV transmission/distribution lines

Industrial power grids

Main distribution networks

Features:
Longer creepage distance

Higher lightning impulse withstand voltage

Higher power frequency withstand voltage

1. Improved System Reliability
Composite deadend insulators significantly improve the reliability of distribution and transmission lines. Their superior hydrophobic silicone rubber housing helps prevent flashover under contaminated or wet conditions. In addition, the polymer structure reduces the risk of failures caused by vandalism, pole fires, or environmental stresses, thereby minimizing power outages and improving system stability.

2. Reduced Maintenance Requirements
Compared with traditional porcelain or glass insulators, composite deadend insulators require little to no routine maintenance. The hydrophobic surface naturally resists contamination buildup, reducing the need for periodic cleaning or inspection. This greatly lowers maintenance costs and ensures compatibility with existing line hardware and structures.

3. Improved Power Quality
Composite insulators help maintain stable electrical performance by reducing leakage current and minimizing transient voltage losses. Their excellent insulation properties contribute to more consistent voltage levels along the distribution line, improving the overall quality of power delivery.

4. Higher Energy Efficiency
Due to the reduced leakage current and better insulation characteristics, power losses along the line are minimized. This results in improved energy efficiency and reduced operational losses for utilities.

5. Enhanced Safety
Composite deadend insulators are significantly lighter than porcelain insulators, making them easier and safer to transport, handle, and install. Their non-brittle design also reduces the risk of shattering, improving safety for installation crews and maintenance personnel.

6. Long Service Life
The high-quality silicone rubber housing and fiberglass core provide excellent resistance to UV radiation, moisture, and environmental aging. As a result, composite deadend insulators maintain stable mechanical and electrical performance throughout a long service life, even in harsh environments.

7. Lower Life-Cycle Cost
Although the initial purchase price may be comparable to conventional insulators, composite deadend insulators offer lower total life-cycle costs. Reduced maintenance, lower installation costs, improved reliability, and longer service life all contribute to significant cost savings over time compared with porcelain insulators.

Different manufacturing processes result in different product performance and appearances. Many manufacturers currently employ a double-seal structure at the ends, effectively protecting the ends from moisture erosion and preventing brittle fracture of the mandrel. Due to the use of a high-temperature sheath at the ends, the resistance to electrolytic aging is significantly improved compared to room-temperature adhesives when corona discharge occurs.

Composite insulators require extremely high sealing performance from their end fittings to ensure mechanical strength, electrical performance, and long-term reliability. Poor sealing allows moisture or contaminants to enter, leading to premature insulator failure. The main reasons can be understood from the following aspects:

1️⃣ Preventing Moisture Ingress into the Fiberglass Core

The core of a composite insulator is a fiberglass reinforced epoxy resin (FRP) core.

If the seal between the end fitting and the core is inadequate, moisture can enter the core along the interface, potentially causing:

Core resin hydrolysis

Decreased mechanical strength

Core cracking

Ultimately, brittle fracture may occur, one of the most serious failure modes for composite insulators.

2️⃣ Preventing Partial Discharge

When moisture or air enters the gap between the end fitting and the core, partial discharge can easily occur under operating voltage, causing:

Aging of the insulation material

Interface carbonization

Degraded electrical performance

Long-term operation may lead to flashover or insulation breakdown.

3️⃣ Prevent Electrochemical Corrosion

If moisture, salt spray, or contaminants enter the fittings, the following may occur under the influence of an electric field:

Electrochemical corrosion

Damage to the interface between the fitting and the mandrel

Destruction of the adhesive layer or crimp structure

This reduces the mechanical load-bearing capacity of the insulator.

4️⃣ Ensure Long-Term Sealing Reliability

Composite insulators are typically designed for a lifespan of 25–40 years and are exposed to:

Rainwater

Ultraviolet radiation

Temperature changes

Environmental pollution (coastal areas, industrial zones)

Therefore, the fitting seal must remain stable over the long term; otherwise, the insulator's lifespan will be significantly reduced.

5️⃣ Prevent Interface Aging and Creepage Problems

Poor sealing can lead to:

Moisture accumulation at the interface

Increased interface electric field

Creeppage or localized carbonization

Thus affecting insulation performance.

From the product appearance, it is possible to identify differences in manufacturing process and material cost. For example, the sealing quality between the end fittings and the FRP rod, and the high-temperature vulcanized (HTV) silicone rubber housing, can enhance the hydrophobicity of the insulator.