ACSS Conductor

South Africa – Eskom 400kV Transmission Upgrade (ACSS Conductor & Accessories Export Case)
Utility Profile
Eskom, South Africa’s national utility, operates more than 33,000 km of transmission lines, supplying 95% of national demand and supporting regional transmission in Southern Africa. Its upgrade of the Gauteng 400 kV network aimed to increase capacity on existing corridors while maintaining compliance with modern clearance and sag requirements.

Product link：https://cable-uni.com/products/bare-conductor/acss-aluminum-conductor-steel-supported.html

Conductor Application
For this project, Eskom required ACSS conductors with high thermal performance:
Continuous operation at 210°C
Emergency operation up to 240°C
Minimal sag increase at high temperature
Corrosion resistance suitable for inland and coastal exposure
After evaluation, Uni-Cable supplied:
ACSS/TW 430 mm² (Aluminum alloy + steel core 30%)
Nominal tensile strength: 43.5 kN
DC resistance at 20°C: 0.0701 Ω/km
Maximum sag at 210°C: < 1.25 m/300 m span
Standard: IEC 61089 / ASTM B857

Project Scope:
Johannesburg 400 kV loop reinforcement
Total: 120 circuit km
Installed on existing towers from 1980s
Required zero tower replacement — saving project cost and time

Accessories Supplied:
In addition to ACSS conductors, Uni-Cable delivered all required hardware:

Product Type	Model / Specification	Qty
Suspension Clamp	XG-400 for ACSS 430 mm²	1,200 pcs
Tension Clamp	NG-400 for ACSS 430 mm²	1,100 pcs
Spacer Damper	SD-500	950 pcs
Vibration Damper	FD-4 for 400-450 mm²	2,400 pcs
Armor Rod	AR-400	2,400 pcs
Polymer Insulator	220 kN Composite, 400 kV	1,000 pcs
Corona Ring	CR-400	1,000 sets

Testing & Quality:

All ACSS conductors tested to IEC 61089 & ASTM B857
Mechanical tension tests: certified tensile strength 43.5 kN
Sag & elongation tests at 210°C & 240°C
Full type tests & batch routine tests on all accessories
Packing: Steel drums, anti-corrosion wrap, IEC 104-2 compliant
Factory ISO 9001, ISO 14001, ISO 45001 certified

Why Eskom Chose Uni-Cable:

Factory direct supply — reduced project cost by 12% vs local alternatives

Proven on-time delivery — 8 weeks ex-works

Full traceability, lot-wise test reports provided

Experience: Uni-Cable had previously supplied over 500 km of ACSS & ACSR to Southern Africa

Strong after-sales technical support, including stringing tension calculation assistance

By partnering with Uni-Cable, Eskom achieved its goal of increasing capacity by 50% on existing infrastructure, delivering power reliability to urban centers with no need for tower modification. The project success reinforced Uni-Cable’s reputation as a reliable supplier of ACSS conductors, fittings, and accessories for Africa’s growing transmission needs.

MVCC/MVC Medium Voltage Covered Conductors in South Africa

Back To List