H1: XMP-120 Suspension Insulator (U120BL) Aerodynamic Type — 120kN, 300mm Creepage, 105kV Lightning Impulse, Brown/Gray Glaze, IEC 60383
The XMP-120 Suspension Insulator (U120BL) Aerodynamic Type is an ultra-high-strength cap-and-pin porcelain insulator engineered for medium‑voltage AC overhead transmission and distribution lines requiring maximum mechanical capacity.
Its distinctive aerodynamic profile reduces wind loading while the 120kN rating delivers the highest strength in the XMP series for the most extreme applications.
Manufactured in compliance with IEC 60383 international standards, this suspension insulator features a robust porcelain body with a standard cap-and-pin design.
The unit is available in either brown (standard) or gray (optional) glaze, both offering identical mechanical and electrical performance.
With a combined mechanical and electrical (M&E) failing load of 120kN and a creepage distance of 300mm, the XMP-120 delivers dependable performance on 33–66 kV lines in standard rural, suburban, and mildly polluted environments — offering a significant 50kN strength advantage over standard 70kN class insulators and 20kN over 100kN class insulators.
The aerodynamic design incorporates optimized shed geometry that minimizes wind resistance and promotes rainwater runoff. This reduces maintenance requirements while ensuring stable insulation performance.
Whether you are designing lines for extreme icing zones, long-span crossings, or heavily loaded strain towers, the XMP-120 suspension insulator offers a durable, ultra-high-strength choice for your infrastructure, with the flexibility to select your preferred glaze color.
H2: XMP-120 Suspension Insulator — Technical Specifications (Brown & Gray Glaze)
The XMP-120 suspension insulator is rated with a combined mechanical and electrical (M&E) failing load of 120kN, making it suitable for tangent suspension, light‑tension, strain, and dead‑end applications on 33–66 kV overhead lines where maximum mechanical strength is required.
Its nominal creepage distance of 300mm provides adequate pollution flashover performance in standard environments. The dry lightning impulse withstand voltage reaches 105kV (positive polarity), and the power frequency wet withstand voltage is 40kV.
The nominal diameter is 350mm, with a spacing (height) of 146mm. The aerodynamic profile reduces wind loading by approximately 15–20% compared to standard disc designs, improving self‑cleaning and reducing tower loads.
The coupling hardware is the standard 16 ball‑and‑socket type, ensuring full interchangeability with existing fittings per IEC dimensional requirements.
The glaze is available in both brown (standard) and gray (optional). All other technical parameters — mechanical, electrical, and dimensional — are identical between the two color options.
Every unit undergoes a routine proof test load of 60kN and an impact strength test of 10Nm to verify mechanical integrity prior to dispatch. Power frequency puncture voltage reaches 120kV, and radio interference voltage (RIV) is exceptionally low at just 50μV at 1000 kHz.
H2: XMP-120 Suspension Insulator — Complete Technical Data (Brown vs. Gray Glaze)
The following table lists all technical parameters for both glaze color options. All values are identical except for the glaze color.
| Parameter | XMP-120 (Brown Glaze) | XMP-120 (Gray Glaze) |
| Glaze Color | Brown | Gray |
| Type Designation | XMP-120 (U120BL) | XMP-120 (U120BL) |
| Figure / Profile | Aerodynamic Type | Aerodynamic Type |
| Diameter D (mm) | 350 | 350 |
| Spacing H (mm) | 146 | 146 |
| Creepage Distance (mm) | 300 | 300 |
| Coupling Size | 16 | 16 |
| Combined M&E Strength (kN) | 120 | 120 |
| Routine Proof Test Load (kN) | 60 | 60 |
| Impact Strength (Nm) | 10 | 10 |
| Power Frequency Dry Withstand Voltage (kV) | 70 | 70 |
| Power Frequency Wet Withstand Voltage (kV) | 40 | 40 |
| Dry Lightning Impulse Withstand Voltage (kV) | 105 | 105 |
| Power Frequency Puncture Voltage (kV) | 120 | 120 |
| Test Voltage RMS to Ground (kV) | 10 | 10 |
| Maximum RIV at 1000 kHz (μV) | 50 | 50 |
| Net Weight, Approximate (kg) | 7.2 | 7.2 |
| Applied Standard | IEC 60383 | IEC 60383 |
Note: The aerodynamic profile of the XMP-120 suspension insulator reduces wind loading by approximately 15–20% compared to standard disc designs. The 120kN rating delivers ultra-high mechanical strength — 50kN higher than standard 70kN class insulators — making it ideal for extreme long spans, heavy icing zones, and strain/dead-end towers. Both brown and gray glazes offer the same outstanding performance.
H2: XMP-120 Suspension Insulator — Material and Construction
Each XMP-120 suspension insulator unit is produced from high‑grade porcelain, fired at over 1,300 °C using the wet process, achieving maximum density and near‑zero porosity.
The cap-and-pin design features a porcelain body with a standard metal cap and pin. The metal components are manufactured from malleable cast iron and hot‑dip galvanised steel, providing excellent corrosion resistance in diverse atmospheric conditions.
The cement bonding between the porcelain body and metal parts uses high‑quality Portland cement, guaranteeing mechanical stability across extreme thermal cycling.
The aerodynamic shed profile is carefully engineered to reduce wind resistance and facilitate self‑cleaning through rainwater runoff. The hard, glossy glaze — available in brown or gray — further enhances self‑cleaning and maintains surface integrity over decades of service.
Both glaze colors are applied using the same high‑quality process, ensuring identical durability, hardness, and electrical performance. The choice between brown and gray is purely aesthetic or based on regional preference.
H2: XMP-120 Suspension Insulator — Applications and Installation
The XMP-120 suspension insulator is widely deployed on 33 kV to 66 kV AC overhead transmission and distribution lines, as well as substation entry towers and switching stations where mechanical demands are at their highest.
The 120kN mechanical rating — the highest in the XMP series — makes it particularly suitable for:
- Extreme long-span lines – Such as river crossings, valley spans, and mountainous terrain where conductor weight and tension are maximized.
- Heavy icing zones – Where ice accretion adds significant weight and mechanical stress, often exceeding the capacity of standard 70kN or 100kN insulators.
- High wind load areas – Where combined wind and ice loading demand maximum mechanical strength.
- Strain, angle, and dead‑end towers – Where mechanical capacity requirements far exceed standard suspension applications.
Its aerodynamic profile offers additional advantages in:
- Coastal regions – Where high winds and salt spray are common; the reduced wind loading minimizes swing and mechanical stress on towers.
- High-wind corridors – Open plains, mountain passes, and offshore-influenced areas where standard discs may experience excessive wind-induced movement.
Typical application scenarios include:
- 33 kV lines – Double suspension strings or strain applications in extreme environments.
- 66 kV lines – Strain, dead‑end, and heavy-angle towers where maximum mechanical strength is non‑negotiable.
- Substation entries – Reliable insulation for heavy-duty strain and dead‑end towers in the most demanding locations.
The standard 16 ball‑and‑socket coupling ensures compatibility with existing clevis pins, yokes, and socket hardware. The compact design facilitates easy hot‑stick handling for live‑line maintenance, minimizing system downtime during replacements.
For higher voltage requirements, multiple units of the XMP-120 suspension insulator can be assembled in strings. Explore our full range of suspension insulators and transmission hardware for more options.
H2: XMP-120 Suspension Insulator — Quality and Performance Advantages
The XMP-120 suspension insulator represents the pinnacle of mechanical strength in our aerodynamic suspension insulator series. Its 120kN rating delivers a 50kN (71%) advantage over standard 70kN insulators, a 40kN (50%) advantage over 80kN class insulators, and a 20kN (20%) advantage over 100kN class insulators.
At just 7.2kg, the XMP-120 offers an exceptional strength-to-weight ratio for a 120kN class insulator. The weight increase over the 100kN version (6.7kg) is only 0.5kg, representing minimal additional tower loading for substantial mechanical gain.
The aerodynamic shed design further enhances performance by reducing wind loading by approximately 15–20%, minimizing insulator swing and reducing mechanical stress on tower structures — a critical benefit when operating at the highest mechanical ratings.
The solid porcelain body ensures excellent dielectric strength, with a power frequency puncture voltage of 120kV demonstrating robust insulation integrity. Radio interference voltage (RIV) is exceptionally low at just 50μV at 1000 kHz, ensuring minimal electromagnetic interference with nearby communication systems.
With an expected service life exceeding 50 years under normal operating conditions, the XMP-120 requires minimal routine maintenance. Every unit undergoes 100% routine testing before dispatch, including:
- Visual and dimensional inspections.
- Routine proof test load verification (60 kN).
- Impact strength testing (10 Nm).
- Power‑frequency wet and dry withstand voltage tests.
- Porosity and temperature‑cycle prototype testing per 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 XMP-120 suspension 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: XMP-120 Suspension Insulator — Why Choose Our Product?
Selecting the right suspension insulator for your transmission infrastructure is critical to long‑term grid reliability — especially in extreme long-span, heavy icing, or mechanically demanding environments. Our XMP-120 suspension insulator is manufactured under stringent quality control protocols at every production stage.
From raw material sourcing (high‑grade porcelain clay) to final high‑voltage electrical testing, every step aligns with IEC 60383. We understand that river crossings, mountain spans, and dead‑end towers can push standard 70kN, 80kN, or even 100kN insulators beyond their safe operating limits.
That is why the XMP-120 suspension insulator is specifically engineered with a 120kN mechanical rating — the highest in our aerodynamic series — combined with an aerodynamic profile to reduce wind loading while improving self‑cleaning performance. Additionally, we offer both brown and gray glaze options to match regional preferences or project specifications.
With over a decade of 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 XMP-120 suspension insulator (brown or gray) is available with short lead times. Contact us today to discover how the XMP-120 suspension insulator can strengthen your grid reliability in the most extreme mechanical environments.


