BS 7835 3.8/6.6kV LSZH Armoured Power Cable XLPE Insulated AWA/SWA Medium Voltage Cable for Direct Burial

When engineers, EPC contractors, and utility companies search for a medium voltage armoured cable for direct burial, the BS 7835 3.8/6.6kV LSZH Armoured Power Cable is often at the top of the list.
But what exactly is this cable, how is it constructed, and why is it widely specified in power networks across Southeast Asia, including Indonesia?

What Does BS 7835 Mean for a Medium Voltage Armoured Cable?

BS 7835 is a British Standard that specifies low smoke zero halogen (LSZH) power cables designed to reduce toxic gas emission, smoke density, and fire propagation.

For medium voltage (MV) applications, BS 7835 cables are chosen when:

• Fire safety is critical

• Underground or enclosed spaces are involved

• Human safety and asset protection are priorities

This makes BS 7835 especially relevant for urban power networks, industrial plants, and infrastructure projects in Indonesia, where safety regulations are becoming stricter.

What Is the Structure of a BS 7835 3.8/6.6kV Armoured Cable?

The performance of this cable comes from its layered engineering design, optimized for mechanical strength, electrical reliability, and fire safety.

How Is the Conductor Designed?

• Class 2 stranded compacted copper conductor

• Offers low resistance, high current capacity, and mechanical robustness

• Complies with IEC/EN 60228

Why Is XLPE Used for Insulation and Screens?

• XLPE (Cross-Linked Polyethylene) insulation rated at 90°C

• Semi-conductive XLPE screens ensure:

  • Uniform electric field

  • Reduced partial discharge risk

  • Stable long-term MV performance

What Role Does the Metallic Screen Play?

• Concentric copper wires with copper tape

• Provides:

  • Earth fault current path

  • Electromagnetic shielding

  • Improved system safety

Why Are LSZH Inner and Outer Sheaths Important?

• Low Smoke Zero Halogen (LSZH) materials:

  • Minimal smoke generation

  • No corrosive halogen gases

• Critical for substations, tunnels, power corridors, and industrial zones

What Is the Difference Between AWA and SWA Armour?

• Single-core: AWA (Aluminium Wire Armour)
  → Avoids magnetic losses

• Multi-core: SWA (Galvanised Steel Wire Armour)
  → Superior mechanical protection

What Are the Key Technical Specifications of BS 7835 3.8/6.6kV Cable?

What Are the Electrical Ratings?

• Voltage rating (Uo/U/Um): 3.8/6.6 (7.2) kV

• AC test voltage: 15 kV

• Maximum conductor temperature:

  • Continuous: 90°C

  • Short circuit: 250°C

What Are the Bending Radius Requirements?

These limits are crucial during installation in Indonesian soil conditions, which often involve tight trenches.

Where Is BS 7835 3.8/6.6kV Armoured Cable Commonly Used?

Why Is It Suitable for Direct Burial?

• Heavy-duty armour resists:

  • Soil pressure

  • Stones and backfill

  • Accidental excavation damage

• LSZH sheath resists:

  • Moisture

  • UV exposure

  • Chemical contamination

Typical Applications in Indonesia

• PLN distribution networks

• Industrial estates (Java, Batam, Bekasi)

• Cement plants and smelters

• Power supply for oil & gas facilities

• Substation interconnections

What Is a Real Indonesian Case Study Using BS 7835 Cable?

Industrial Power Upgrade in West Java

A manufacturing park in West Java upgraded its 6.6kV underground power network to meet new fire safety standards.

Why BS 7835 Was Selected:

• Direct burial without concrete ducts

• LSZH compliance for emergency evacuation routes

• Long-term thermal stability

Results:

• Reduced maintenance incidents

• Improved safety audit scores

• Lower insurance risk classification

Frequently Asked Questions (FAQ)

Is BS 7835 cable suitable for tropical climates like Indonesia?

Yes. XLPE insulation and LSZH sheath perform well under high humidity and temperature.

Can this cable be installed without ducts?

Yes. It is designed for direct burial.

Is BS 7835 mandatory in Indonesia?

Not mandatory, but increasingly specified in high-risk and high-value projects.

Single-core or three-core: which should I choose?

• Single-core: Higher current, flexible layout

• Three-core: Compact installation, simpler termination

What Should You Consider Before Selecting BS 7835 3.8/6.6kV Cable?

• Load current and future expansion

• Installation environment

• Fire safety requirements

• Soil conditions

• Compliance with project specifications

If you are designing or upgrading a 6.6kV power system and need a reliable LSZH armoured cable for direct burial, BS 7835 3.8/6.6kV XLPE AWA/SWA cable is a proven solution.

👉 Contact a professional cable supplier for:

• Cable sizing support

• Technical datasheets

• Project-specific recommendations

• Compliance documentation

Choosing the right cable today ensures safety, reliability, and long-term performance for your power network.