H1: 15003 Long-Rod Insulator Suspension Porcelain — 70kN, 550mm Creepage, IEC 60383
The 15003 long-rod insulator suspension porcelain is a robust, high‑strength solution engineered for medium‑ to high‑voltage AC overhead transmission lines. It delivers outstanding mechanical endurance and reliable electrical insulation in demanding environments.
Fully compliant with IEC 60383 international standards, this long‑rod insulator features a one‑piece porcelain body that eliminates internal metallic components. This design minimizes radio interference and ensures uniform voltage distribution across the string.
With a mechanical failing load of 70kN and a creepage distance of 550mm, the 15003 long‑rod insulator provides dependable performance in standard industrial, rural, and mildly polluted coastal areas.
The long‑rod profile is smooth and self‑cleaning, reducing maintenance needs while maintaining stable insulation under extreme temperatures from ‑70°C to +105°C.
Whether you are upgrading existing lines or planning new transmission projects, the 15003 long-rod insulator offers a durable and cost‑effective choice for your grid infrastructure.
H2: 15003 Long-Rod Insulator — Technical Specifications
The 15003 long-rod insulator is rated with a combined mechanical and electrical (M&E) failing load of 70kN. This makes it ideally suited for tangent suspension and light‑tension applications on 66–110 kV lines.
Its nominal creepage distance of 550mm ensures adequate pollution flashover performance in moderately contaminated areas. The dry lightning impulse withstand voltage reaches 170kV (positive polarity). The nominal diameter is 180mm, and the overall height is 423mm.
The coupling hardware is the standard 16L ball & socket type. This ensures full interchangeability with existing fittings per IEC dimensional requirements.
The glaze is offered in both brown (standard) and gray (optional). Every unit undergoes a rigorous porosity test at 180MPa·h to certify zero porosity, as mandated by IEC 60383.
H2: 15003 Long-Rod Insulator — Complete Technical Data (per IEC 60383)
The following table lists all technical parameters for both glaze color options. All values are identical except for the glaze color.
| Parameter | 15003 (Brown Glaze) | 15003 (Gray Glaze) |
| Glaze Color | Brown | Gray |
| Figure No. | 2 | 2 |
| Height (mm) | 423 | 423 |
| Nominal Diameter D (mm) | 180 | 180 |
| Creepage Distance (mm) | 550 | 550 |
| Mechanical Failing Load (kN) | 70 | 70 |
| Routine Tensile Load (kN) | 56 | 56 |
| Coupling Size | 16L (Ball & Socket) | 16L (Ball & Socket) |
| Temperature Cycle Test | 70K / 3 times | 70K / 3 times |
| Porosity Test | 180 MPa·h | 180 MPa·h |
| Power‑freq. Wet Withstand Voltage (kV) | 70 | 70 |
| Dry Lightning Impulse Withstand Voltage (kV) | 170 | 170 |
| Net Weight (kg) | 10.0 | 10.0 |
| Applied Standard | IEC 60383 | IEC 60383 |
Note: Long‑rod insulators offer superior self‑cleaning and lower maintenance compared to equivalent multi‑disc strings.
H2: 15003 Long-Rod Insulator — Material and Construction
Each 15003 long-rod insulator unit is produced from high‑grade alumina porcelain. It is fired at over 1,300 °C using the wet process. This achieves maximum density and near‑zero porosity — verified through the 180 MPa·h porosity test.
The single‑piece porcelain rod ensures excellent dielectric strength. The metal end‑fittings (cap and pin) are manufactured from malleable cast iron and hot‑dip galvanised steel. This provides outstanding corrosion resistance in diverse atmospheric conditions.
The cement bonding between the porcelain body and metal parts uses high‑quality Portland cement. This guarantees mechanical stability across extreme thermal cycling from ‑70 °C to +105 °C.
The hard, glossy glaze (available in brown or gray) promotes self‑cleaning by facilitating rainwater runoff. This significantly reduces the frequency of manual washing and inspection. As a result, the service life of the 15003 long-rod insulator is extended.
H2: 15003 Long-Rod Insulator — Applications and Installation
The 15003 long-rod insulator is widely deployed on 66 kV to 110 kV AC overhead transmission lines, distribution networks, and substation entry towers.
Its 70kN mechanical capacity makes it suitable for both suspension and light‑tension applications. The 550mm creepage distance provides reliable performance in standard rural, suburban, and mildly polluted industrial areas.
Typical application scenarios include:
- 66 kV lines – Single or double suspension strings in areas with moderate mechanical loads.
- 110 kV lines – Suspension and light‑tension strings where mechanical strength is prioritized.
- Substation entries – Reliable insulation for strain and dead‑end towers.
The standard 16L ball‑and‑socket coupling ensures compatibility with existing clevis pins, yokes, and socket hardware. The long‑rod design facilitates easy hot‑stick handling for live‑line maintenance. This minimizes system downtime during replacements.
For higher voltage requirements, multiple units of the 15003 long-rod insulator can be assembled in strings. Explore our full range of suspension insulators and transmission hardware for more options.
H2: 15003 Long-Rod Insulator — Quality and Performance Advantages
Compared to traditional multi‑disc insulator strings, the 15003 long-rod insulator offers a lighter overall weight (just 10.0 kg), fewer components, and improved self‑cleaning properties.
The solid porcelain core eliminates internal air gaps. This effectively prevents puncture failures. It also ensures consistently low radio interference voltage (RIV) throughout its service life.
With an expected service life exceeding 50 years under normal operating conditions, the 15003 requires minimal routine maintenance. Every unit undergoes 100% routine testing before dispatch, including:
- Visual and dimensional inspections.
- Routine tensile load verification (56 kN).
- Power‑frequency wet withstand voltage test (70 kV).
- Porosity and temperature‑cycle prototype testing as specified by IEC 60383.
Each insulator is individually foam‑cushioned and securely packed in durable wooden crates or corrugated cartons. This prevents damage during transit. We offer flexible shipping arrangements (FOB, CIF, EXW) with lead times of 15–30 days, depending on order quantity.
For detailed product datasheets, CAD drawings, or competitive pricing on the 15003 long-rod insulator (brown or gray), please contact our sales team via the inquiry form below.
We also provide OEM services and complimentary technical consultation for string assembly design. For installation guidance, refer to our insulator string assembly guide.
H2: 15003 Long-Rod Insulator — Why Choose Our Product?
Selecting the right long‑rod insulator for your transmission infrastructure is critical to long‑term grid reliability. Our 15003 long-rod insulator is manufactured under stringent quality control protocols at every production stage.
From raw material sourcing (high‑alumina clay) to final high‑voltage electrical testing, every step aligns with IEC 60383. We recognize that transmission line outages result in significant financial losses. That is why each 15003 long-rod insulator is engineered for maximum durability and consistent performance.
With over a decade of specialized experience in porcelain insulator production, we offer competitive factory pricing, prompt delivery, and dedicated after‑sales technical support.
Whether you require a small sample batch for project validation or a full container shipment, the 15003 long-rod insulator (brown or gray) is available with short lead times. Contact us today to discover how the 15003 long-rod insulator can strengthen your grid reliability in standard and mildly polluted environments.


