BS 7835 XLPE LSZH 8.7/15kV Medium Voltage Power Cable for Underground & Duct Installation Flame Retardant, Copper Conductor

When planning a medium-voltage power distribution network, the choice of cable can make or break your project’s safety, reliability, and longevity. One cable that consistently emerges as a top choice in Indonesia and worldwide is the BS 7835 XLPE LSZH 8.7/15kV medium voltage power cable.

What Is BS 7835 XLPE LSZH 8.7/15kV Cable?

BS 7835 refers to a British Standard specification for medium voltage cables designed for fixed installation in underground conduits, ducts, or direct burial. These cables combine cross-linked polyethylene (XLPE) insulation with low smoke zero halogen (LSZH) sheathing, offering superior fire performance and environmental safety. With a voltage rating of 8.7/15kV (Um: 17.5kV), BS 7835 cables are suitable for urban power networks, industrial installations, and high-safety environments where flame retardancy is required.

In Indonesia, where urbanization and industrial expansion drive medium-voltage projects, BS 7835 cables are increasingly used in underground networks to ensure both reliability and safety.

Where Can BS 7835 Cable Be Applied?

BS 7835 cables are designed for medium-voltage networks in a variety of underground or ducted applications:

• Underground urban power distribution: Ideal for cities like Jakarta, Surabaya, or Bandung, where cable ducts are common.

• Industrial plants: Supplying medium voltage to factories, plants, and mining operations.

• Renewable energy projects: Solar farms or hydroelectric plants needing safe, durable medium-voltage cables.

• Substations: Connecting transformers, switchgear, and feeders with mechanical protection.

The LSZH sheath and flame-retardant properties make BS 7835 especially suitable for high-density areas or areas with strict fire safety regulations.

What Are the Advantages of XLPE LSZH Cables?

BS 7835 leverages XLPE and LSZH technology to deliver multiple advantages:

1. High Thermal Performance – Operates up to +90°C continuously.

2. Low Smoke Emission – Critical for underground ducts and populated areas.

3. Zero Halogen – Reduces toxic gases and environmental impact.

4. Mechanical Strength – Armoured layers protect against physical damage.

5. Flame Retardant – IEC/EN 60332-1-2 compliance ensures fire safety.

6. UV Resistant – Suitable for exposed installations.

Compared with PVC or standard XLPE cables, BS 7835 provides higher safety, reliability, and longevity.

How Should BS 7835 Cable Be Installed?

Proper installation ensures optimal performance and longevity:

1. Trench or Duct Preparation: Ensure ducts are clean, smooth, and free from sharp edges.

2. Bending Radius Compliance: Respect minimum bending radius (12–15× overall diameter) especially near joints.

3. Mechanical Protection: Armoured layers protect against external impacts; avoid excessive tension during pulling.

4. Temperature Consideration: Avoid installations in temperatures below 0°C without preheating or heating.

5. Termination and Jointing: Use compatible XLPE terminations and joints with careful stress relief.

6. Testing: Conduct insulation resistance and continuity tests before commissioning.

In Indonesia, case studies show that careful compliance with bending radius and duct preparation reduces installation damage by over 30%.

Frequently Asked Questions (FAQ)

What Does LSZH Mean and Why Is It Important?

LSZH stands for Low Smoke Zero Halogen. During fire, it produces minimal smoke and no halogen gases, improving safety in enclosed or underground spaces.

Can BS 7835 Cable Be Buried Directly in Soil?

Yes, BS 7835 can be installed in free-draining soil, but armouring is recommended for mechanical protection. Use sand bedding and warning tapes to avoid damage from digging.

How Does BS 7835 Handle Flame and Fire?

It meets IEC/EN 60332-1-2, which ensures flame retardancy. Even in ducts, the cable will not propagate fire along its length.

How Do I Choose Between Single-Core and Multi-Core Versions?

• Single-core: Preferred for high-current applications; use AWA aluminium armour.

• Three-core: Common for three-phase networks; SWA steel wire armour provides additional mechanical strength.

What Are Typical Indonesian Applications?

• Urban medium-voltage distribution: Jakarta MRT underground networks.

• Industrial parks: Surabaya and Batam factories for reliable power supply.

• Renewable energy plants: Bali solar and hydro projects requiring fire-safe medium-voltage cabling.

How Does BS 7835 Compare Cost-Wise to Other Medium-Voltage Cables?

While slightly more expensive than PVC-insulated cables, BS 7835 offers long-term cost savings due to reduced fire risk, lower maintenance, and longer operational life.

Can BS 7835 Cable Be Installed Outdoors?

Yes, it is UV resistant, but exposure should be minimized. Prefer LSZH outer sheath facing upwards or shielded areas.

How Long Does BS 7835 Cable Last?

With proper installation, BS 7835 cables have a lifespan of 25–30 years, even in underground or ducted applications, outperforming standard PVC or rubber-insulated cables.

BS 7835 Cable in Indonesian Underground Networks

A major substation in Jakarta upgraded its medium-voltage feeder network using BS 7835 3-core 240 mm² XLPE LSZH cables. Key benefits included:

• Reduced fire risk in densely populated urban areas.

• Minimal installation damage due to proper armouring and LSZH sheathing.

• High reliability during rainy seasons, maintaining stable voltage supply.

• Enhanced compliance with local fire safety regulations.

This real-world example demonstrates BS 7835’s suitability for urban and industrial underground projects.

Why Choose BS 7835 for Your Medium-Voltage Project?

• Complies with BS 7835, IEC/EN 60228, and flame retardant standards.

• LSZH sheath reduces smoke and toxic gas risk.

• Suitable for underground, ducted, or industrial applications.

• Strong armouring protects against mechanical damage.

• Proven performance in Indonesian urban and industrial installations.

For safe, reliable, and fire-resistant medium-voltage power distribution, choose BS 7835 XLPE LSZH cables. Contact our local Indonesian distributors to discuss cable sizes, armouring options, and tailored installation support.