Optical transmission hardware integration one-stop service provider
Views: 0 Author: Tina Publish Time: 2026-09-30 Origin: Site
In high-voltage power transmission networks, power utilities and grid engineers face the dual challenge of protecting overhead transmission towers from lightning strikes while building high-bandwidth, long-distance communication backbones. Selecting the right OPGW fiber cable (Optical Ground Wire) provides the ultimate integrated solution. By combining conventional overhead ground wire shielding with ultra-low-loss optical fibers enclosed in a hermetically sealed stainless steel tube, this advanced cable design guarantees maximum electrical safety, exceptional mechanical load resistance, and reliable optical data transmission over long spans.
An OPGW fiber cable is an optical ground wire engineered to replace traditional static/shield wires at the topmost position of high-voltage transmission towers. Its specialized multi-layer construction protects sensitive optical fibers from short-circuit heat and extreme environmental stress.
At the heart of the cable structure is a laser-welded stainless steel tube (SUS tube, 3.90 mm3.90 mm diameter) that provides a rugged, pressure-resistant, and hermetically sealed chamber for 24 ITU-T G.652.D single-mode optical fibers. The tube interior is completely filled with thixotropic anti-vibration filling grease to prevent water vapor ingress and cushion the optical fibers against mechanical shock.
Surrounding the central 20.3% AS20.3% AS wire (3.90 mm3.90 mm), the inner layer incorporates 5 aluminum-clad steel (AS) wires alongside the stainless steel optical unit. The outer layer utilizes high-conductivity aluminum alloy (AA) and aluminum-clad steel (AS) wires stranded in a right-hand Z-stranding direction over a total bearing cross-sectional area of 215.0 mm2215.0 mm2 (AS area:71.68 mm2AS area:71.68 mm2, AA area:143.35 mm2AA area:143.35 mm2). This metallic matrix complies with IEEE 1138 and IEC 60794 standards to provide both superior axial mechanical tensile strength and low electrical resistance.
When reviewing technical datasheets for an OPGW cable, power utilities must evaluate four core engineering parameters:
As an overhead ground wire, the cable must safely dissipate direct lightning strikes and high fault currents to the ground without overheating the internal optical fibers:
Short-Circuit Current Rating: 40 kA40 kA (for 0.25 s0.25 s over 20℃20℃ to 200℃200℃).
Short-Circuit Current Capacity (I2tI2t): 388.8 kA2s388.8 kA2s.
Direct-Current (DC) Resistance: Ultra-low resistance of 0.2 Ω/km0.2 Ω/km, minimizing power loss and thermal buildup during grounding.
OPGW cables must endure severe environmental loads, including high-velocity gale-force winds, heavy ice accretion, and expansive river or valley crossings:
Rated Tensile Strength (RTS): 126.5 kN126.5 kN.
Ultimate Tensile Strength (UTS): 135.5 kN135.5 kN.
Maximum Allowable Working Stress (MAT, 40% RTS): 235.3 N/mm2235.3 N/mm2.
Daily Stress (EDS, 20% to 25% RTS): 117.7 to 147.1 N/mm2117.7 to 147.1 N/mm2.
Young's Modulus (E-Modulus): 97.3 kN/mm297.3 kN/mm2 with a thermal expansion coefficient of 17.5×10−6/℃17.5×10−6/℃.
Cable Dimensions: Outer diameter of 19.50 mm19.50 mm with a nominal weight of 892 kg/km892 kg/km.
Manufactured with 24-core single-mode G.652.D optical fibers, the finished cable delivers superior transmission metrics:
Optical Attenuation: ≤0.38 dB/km≤0.38 dB/km at 1310 nm1310 nm and ≤0.195 dB/km≤0.195 dB/km at 1550 nm1550 nm (enabling unrepeatered ultra-long span data links).
Polarization Mode Dispersion (PMD): ≤0.2 ps/(km)0.5≤0.2 ps/(km)0.5.
Proof Test Level: ≥0.69 GPa≥0.69 GPa.
Standard 12-Color Sequence: Blue, Orange, Green, Brown, Grey, White, Red, Black, Yellow, Purple, Pink, Aqua.
Operating & Transport Temperature Window: −40℃−40℃ to +80℃+80℃.
Installation Temperature Range: −10℃−10℃ to +50℃+50℃.
Minimum Bending Radius: 487 mm487 mm under construction and 292 mm292 mm during fixed operation.
Installing an OPGW fiber cable requires specialized high-voltage tension and suspension hardware fittings to ensure structural integrity across tower spans:
Helical preformed aluminum-clad steel tension grips are designed to support up to 100% RTS100% RTS without crushing the internal stainless steel optical unit.
Preformed suspension clamps with elastomer inserts minimize static bending stress at intermediate towers. Stockbridge-type vibration dampers are essential for mitigating wind-induced Aeolian vibration and sub-span oscillation across long spans.
Dedicated tower-leg clamps route the cable safely down high-voltage lattice towers into weatherproof metallic Fiber Optic Splice Closures (FOSC) and substation Optical Distribution Frames (ODF) for fusion splicing.
Specification Parameter | OPGW Cable | ADSS Cable | OPPC Cable |
|---|---|---|---|
Installation Location | Top of High-Voltage Towers (Ground Wire Position) | Below Power Phase Conductors (Induction Field) | Phase Conductor Position (Replaces Phase Wire) |
Core Structure | Stainless Steel Tube + AS / AA Stranded Wires | All-Dielectric + Aramid Yarn + PE / AT Sheath | Stainless Steel Tube + Phase Conductor Stranding |
Lightning & Grounding Role | Primary Ground Wire (40 kA40 kA Short-Circuit Rating) | No Grounding Function (Non-metallic) | Carries Full Phase Current |
Tensile Strength (RTS) | Very High (126.5 kN126.5 kN, Steel Core) | Moderate (Aramid Yarn Reinforcement) | High (Phase Conductor Strength) |
Space Potential & Tracking | Immune to Electrical Tracking (Metallic) | Requires Anti-Tracking (AT) Jacket (>110 kV>110 kV) | Operates at High Voltage Potential |
Primary Application | 110 kV∼1000 kV110 kV∼1000 kV Transmission Lines | 10 kV∼220 kV10 kV∼220 kV Distribution Lines | Lines with No Ground Wire / Single-Pole Lines |
Selecting the right OPGW fiber cable is crucial for ensuring the uninterrupted operation of both high-voltage power grids and smart telecommunication backbones. By carefully aligning your design with short-circuit current requirements (such as 40 kA/388.8 kA2s40 kA/388.8 kA2s), mechanical rated tensile strength (126.5 kN126.5 kN), and 24-core low-loss single-mode fibers, power utilities achieve a 30+ year maintenance-free operational lifespan.
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