BS 7835 XLPE LSZH 12.7/22kV Cable

What is BS 7835 XLPE LSZH 12.7/22kV Cable?

The BS 7835 XLPE LSZH 12.7/22kV cable is a medium voltage cable designed for reliable electricity transmission in underground, indoor, and ducted installations. It uses cross-linked polyethylene (XLPE) insulation combined with a low smoke zero halogen (LSZH) outer sheath, making it ideal for high-safety applications where fire safety and toxic fume reduction are critical.

This cable is widely used in South Africa’s mining sector, urban power networks, and industrial plants, offering durability under mechanical, thermal, and environmental stress. Its voltage rating of 12.7/22 kV (Um 24 kV) positions it perfectly for medium voltage distribution, connecting substations to localized transformers or heavy equipment. 

Applications in South Africa

BS 7835 XLPE LSZH 12.7/22kV cables are ideally suited for South Africa’s medium voltage networks, including:

1. Urban Power Distribution

With urban areas expanding, LSZH cables are preferred in substations, underground networks, and building installations. Their flame-retardant and low-smoke properties mitigate fire risks in residential and commercial zones.

2. Mining Industry

South Africa’s mining sector relies heavily on MV cables to power heavy equipment and underground operations. BS 7835 XLPE LSZH cables provide mechanical protection, thermal resilience, and reduced toxic emissions, critical for underground mine safety.

Case Study: In a recent platinum mine in the Rustenburg region, older PVC-insulated cables were replaced with BS 7835 XLPE LSZH cables. The upgrade reduced cable failures by 40%, minimized maintenance costs, and enhanced worker safety in confined underground tunnels.

3. Industrial Plants

Industrial plants require durable and reliable power delivery. The mechanical strength of steel wire armoured (SWA) multi-core cables allows safe installation in factories, processing plants, and energy-intensive operations.

4. Renewable Energy Integration

South Africa’s growing renewable sector, including solar farms in the Northern Cape and wind farms along the Western Cape coast, benefits from medium voltage LSZH cables. They ensure safe power transmission from generation units to local substations while meeting fire-safety and environmental standards.

Frequently Asked Questions (FAQ)

Q1: Why choose XLPE insulation over PVC?

Answer: XLPE offers superior thermal resistance, higher dielectric strength, and better longevity under continuous electrical stress. Unlike PVC, it does not soften at high temperatures, ensuring reliability in demanding applications.

Q2: What does LSZH mean and why is it important?

Answer: LSZH stands for Low Smoke Zero Halogen. It means the cable emits minimal smoke and no halogenated toxic gases in case of fire, significantly improving safety in enclosed spaces like mines and urban underground ducts.

Q3: Can these cables be installed outdoors?

Answer: Yes, BS 7835 XLPE LSZH cables are UV resistant, making them suitable for outdoor installations. However, care must be taken to avoid prolonged exposure without mechanical protection.

Q4: How do single-core and multi-core cables differ in application?

Answer: Single-core cables are often used for high-capacity installations and are typically aluminium wire armoured (AWA). Multi-core cables are preferred for distribution networks, offering steel wire armouring (SWA) for mechanical protection.

Q5: Are these cables flame-retardant?

Answer: Yes, they comply with IEC/EN 60332-1-2, ensuring that the cables resist flame propagation, crucial for underground and high-risk environments.

The BS 7835 XLPE LSZH 12.7/22kV cable represents a high-performance, safe, and reliable solution for South Africa’s medium voltage power networks. Its combination of robust construction, XLPE insulation, LSZH sheathing, and international standards compliance makes it ideal for urban power distribution, industrial plants, mining operations, and renewable energy projects.