The Saudi Electricity Company (SEC) is undertaking an ambitious 2030 grid modernization and expansion plan, involving the upgrade and reconductoring of hundreds of kilometers of 380kV and 132kV transmission lines. One such key project in Riyadh and Dammam involved upgrading thermal-limited ACSR conductors to high-temperature, low-sag ACSS (Aluminum Conductor Steel Supported) conductors to increase line capacity without changing tower geometry.
To ensure full reliability and system compatibility, SEC required not just conductors but a complete transmission solution, including fittings, vibration dampers, suspension clamps, and dead-end hardware — all meeting SASO, ASTM, and IEC standards.
Uni-Cable was selected as a preferred cable and fittings supplier due to:
Long-term experience in high-voltage transmission conductors
Full design and manufacturing capability for both cable and hardware
Pre-tested ACSS conductors with E3X-type surface enhancement options
Proven success in Middle Eastern desert conditions
| Conductor Type | Structure | Size | Rated Temp | Standard |
|---|---|---|---|---|
| ACSS/TW Drake | Trapezoidal Aluminum + Steel core | 26/7 (26 Al strands, 7 steel) | Up to 210°C | ASTM B856 / B857 |
| ACSS/E3X Cardinal | Round Al + E3X-enhanced coating | 54/7 | Up to 230°C | ASTM B609 |
| ACSS/AW 795 MCM | Al-clad steel reinforced | 54/7 AW | 210°C | IEC 61089 |
Key Performance Features:
Thermal expansion resistance at 200+°C
Ultra-high tensile strength: >150 kN
Corona-free surface finish
Custom length spooling per span requirement
E3X surface option enhances emissivity, reduces conductor temp by 10–15°C
| Accessory Type | Specification | Standard |
|---|---|---|
| Suspension clamps | 380kV, high-slip resistance, bolted/armor rod type | IEC 61284, SASO 171 |
| Tension clamps | Bolted and compression dead-end | IEC 61284 |
| Vibration dampers | 4R and 6R types with galvanized steel messenger | IEEE 664 |
| Spacer dampers | Inter-phase spacing at wind zones | ASTM A974 |
| Corona rings, grading rings | For anti-corona performance > 380kV | IEC 60815 |
Each fitting was paired per tower type (suspension, tension, angle), pre-packed with installation drawings and torque specs.
SEC East: 180 km of 380kV double circuit line from Dammam to Qatif
Supplied:
760 km of ACSS/TW conductor (Drake & Cardinal sizes)
Over 1,200 sets of fittings, suspension clamps, dampers, spacers, and accessories
Special anti-sand corrosion coating on exposed fittings
Fully aligned with SEC’s SASO and NG-SA technical specification manual
ACSS conductors tested per ASTM B856:
Stress-strain curve
Creep testing at 150°C
DC resistance at 75°C and 200°C
Accessories passed:
Salt-spray test for 1,000 hours
Slip resistance test (≥95% of conductor UTS)
Corona inception < 15 kV
IEC 61284 mechanical vibration endurance
Type Test Certificate from KEMA and internal QA lab provided
Drum type: Treated hardwood with steel reinforcement, 2.8–3.2 m diameter
Markings: Cable code, batch no., conductor size, length, project ID
Fittings boxed per tower type in stainless crates
Export via King Abdulaziz Port (Dammam) with Form A, Packing List, Test Report, Certificate of Origin
Entire delivery completed in two 40 ft HQ containers within 35 days
Full turnkey supply of conductor + matched fittings
Customized conductor drum lengths, reducing waste and field splicing
E3X option for thermal emissivity improvement, lowering system sag
Flexible export packaging, tower-wise accessory pre-grouping
On-site bilingual support and pre-installation inspection service
Better cost-performance ratio than European or US brands, with KEMA validation
SEC reported that Uni-Cable’s ACSS conductors performed exceptionally during peak load in desert summer conditions, with lower sag and temperature rise than legacy ACSR lines. Installation teams found the accessory system well-labeled, easy to install, and appreciated Uni-Cable’s responsive technical service team.
SEC has now registered Uni-Cable as an approved vendor for future 132kV and 380kV ACSS line expansions.
