BS 6708 vs SANS 1520 Mining Cables: Two Standards, Two Design Philosophies – How to Choose the Right Cable for Harsh Mining Environments

Why Mining Cable Standards Matter

Modern mining operations depend heavily on electrically powered mobile equipment. From underground continuous miners and loaders to surface crushers, draglines, and drilling rigs, flexible trailing cables form the lifeline between power supply and production machinery. Any cable failure can lead to unplanned downtime, safety incidents, or costly regulatory non-compliance.

Mining environments are among the harshest industrial settings in the world. Cables are subjected to:

• Continuous dragging and reeling

• Severe mechanical abrasion from rocks and machinery

• Moisture, mud, chemicals, oils, and UV exposure

• Elevated temperatures and electrical stress

• Potentially explosive atmospheres underground

To mitigate these risks, mining-specific cable standards have been developed globally. Among the most influential are:

• BS 6708 – Flexible cables for use at mines and quarries, originating from the UK

• SANS 1520 – Flexible electrical trailing cables for use in mines, issued by South Africa

While both standards address mining and quarrying applications, they differ significantly in design philosophy, voltage coverage, mechanical robustness, and regulatory enforcement.

The purpose of this article is threefold:

1. To explain BS 6708 and SANS 1520 in technical depth

2. To highlight the key structural, electrical, and regulatory differences

3. To provide a practical selection guide for mining engineers, project managers, and procurement teams

Overview of BS 6708 – Flexible Cables for Use at Mines and Quarries

Scope and Background of BS 6708

BS 6708 is a British Standard that specifies the constructional requirements, dimensions, and testing methods for flexible cables used in mines and quarries. The current edition supersedes BS 6708:1991, incorporating updated insulation specifications, revised short-circuit ratings, and additional cable types.

Historically, BS 6708 was developed to support:

• UK coal mining

• Quarrying operations

• Export-oriented mining machinery requiring standardized cable dimensions

The standard places strong emphasis on dimensional consistency and mechanical construction, ensuring interchangeability and predictable installation behavior.

Unlike some national mining standards, BS 6708 is not a legal requirement outside specific jurisdictions, but it remains widely used in quarrying and medium-duty mining projects globally.

Cable Categories Covered Under BS 6708

BS 6708 defines a broad range of cable types, categorized by armouring method, screening, voltage rating, and intended application.

Non-Armoured Flexible Cables (Individually Metallic Screened Cores)

• Voltage ratings: 600/1000 V, 640/1100 V, 1900/3300 V

• Applications:

  Coalface cutters

  Handheld drilling machines

  Overhead catenary systems

Representative types include:
Types 7, 7M, 7S, 11, 14, 16, 43, 44, 307, 307M, 307S, and FS4 flat cables

These cables prioritize flexibility and ease of handling, making them suitable for controlled environments with moderate mechanical stress.

Galvanised Steel Pliable Wire Armoured Cables

This category represents the backbone of BS 6708 trailing and roadway cables.

• Unscreened cores (640/1100 V): Types 20, 21

• Screened or unscreened cores for lighting and control: Types 62, 63, 64, 70, 71

• Screened trailing cables (640/1100 V): Types 201, 211

• Medium-voltage quarry trailing cables (1900/3300 V): Types 321, 331

• Higher-voltage trailing cables (3800/6600 V): Types 621, 630, 631

The galvanized steel wire armouring provides improved crush resistance and tensile strength compared to non-armoured designs.

Auxiliary and Multi-Core Control Cables

• Voltage rating: 320/550 V

• Up to 24 individually screened cores

• Applications: Machine interconnection and auxiliary equipment

Types: 506, 512, 518, 524

These cables are commonly used where signal integrity and control reliability are critical.

Technical Emphasis of BS 6708

BS 6708 is highly detailed in its technical prescriptions, particularly in:

• Cable geometry and dimensional tolerances

• Core identification and colour sequencing

• Electrical testing requirements, including:

  Voltage withstand tests

  Insulation resistance tests

  Wrapping and flexing tests

Annexes within the standard provide additional guidance:

• Annex A: Codes of practice and conductivity data

• Annex B: Recommended current ratings

• Annex C: Short-circuit current carrying capacity of screens

This makes BS 6708 particularly valuable for manufacturers, quality control teams, and engineering consultants.

Typical Use Scenarios for BS 6708 Cables

BS 6708 cables are widely used in:

• Aggregate and limestone quarries

• Coalface cutting equipment

• Mobile crushers and screens

• Underground roadway extensions

• Overhead catenary power systems

They are best suited for medium-duty mechanical environments where standardised dimensions and ease of replacement are priorities.

Overview of SANS 1520 – South Africa’s Benchmark Mining Cable Standard

Regulatory Status and Global Recognition

SANS 1520 is issued by the South African Bureau of Standards (SABS) and is legally mandatory for mining operations in South Africa. Compliance is closely linked to the Mine Health and Safety Act, making non-compliance a significant legal and operational risk.

Due to South Africa’s deep-level mining conditions, SANS 1520 has earned a global reputation for exceptional mechanical durability and safety performance.

Structure of the SANS 1520 Standard

SANS 1520 is divided into three comprehensive parts:

• Part 1: Low-voltage AC trailing cables

  640/1100 V

  1.9/3.3 kV

• Part 2: Medium- and high-voltage AC trailing cables

  3.8/6.6 kV up to 19/33 kV

• Part 3: DC trailing cables

  Up to 1.5 kV DC

This wide voltage coverage is one of the defining strengths of SANS 1520.

Typical SANS 1520 Cable Types and Applications

Construction Philosophy of SANS 1520 Cables

SANS 1520 cables are engineered for extreme duty cycles, with construction features that go beyond many international standards:

• Class 5 tinned copper conductors for superior flexibility

• EPR or XLPE insulation systems with high thermal endurance

• Heavy-duty elastomeric sheaths (CR or TPU)

• Mandatory pilot cores for earth continuity monitoring

• Reinforcement systems, including textile braid, copper braid, and optional aramid (Kevlar)

This holistic approach integrates electrical performance, mechanical resilience, and safety monitoring into a single cable system.

Technical Comparison: BS 6708 vs SANS 1520

Voltage Coverage

• BS 6708: Typically up to 3.3 kV, with limited 6.6 kV quarry types

• SANS 1520: Comprehensive coverage from 640 V to 33 kV, including DC systems

Mechanical and Environmental Performance

• BS 6708:

  Optimised for standardized construction

  Suitable for moderate mechanical stress

• SANS 1520:

  Designed for continuous reeling, dragging, torsion

  Superior abrasion, moisture, and heat resistance

Safety and Monitoring Features

• BS 6708:

  Metallic screening for fault control

  Limited pilot core integration

• SANS 1520:

  Mandatory pilot cores

  Enhanced flame resistance, low smoke, low toxicity

  Alignment with mine safety interlocking systems

Regulatory and Operational Context

• BS 6708: Widely accepted but generally voluntary

• SANS 1520: Legally enforced in South Africa and strongly preferred internationally for high-risk mining environments

Practical Applications in Mining Operations

South African Underground Platinum Mine (SANS 1520)

A deep-level platinum mine in Limpopo deployed Type 611 6.35/11 kV SANS 1520 trailing cables for mobile drilling rigs.

Results:

• Improved uptime due to fatigue-resistant design

• Reduced earth-fault incidents via pilot core monitoring

• Extended cable service life beyond 10 years

Aggregate Quarry Operation (BS 6708)

A UK-based aggregate quarry selected BS 6708 Type 321 trailing cables for mobile crushers.

Benefits:

• Standardised dimensions simplified spares management

• Lower initial cost compared to heavy-duty mining cables

• Suitable performance for controlled quarry conditions

Selecting the Right Standard for Your Mining Project

When BS 6708 Is Appropriate

• Quarrying and aggregate operations

• Low to medium voltage requirements

• Moderate mechanical stress

• Projects prioritising dimensional standardisation

When SANS 1520 Is Mandatory or Recommended

• South African mining operations

• Deep-level or high-risk underground mines

• Medium- and high-voltage mobile equipment

• Applications requiring pilot core protection

Key selection factors include:

• Voltage level

• Equipment mobility

• Regulatory jurisdiction

• Safety risk profile

• Total lifecycle cost

Conclusion

Although BS 6708 and SANS 1520 both serve mining and quarrying industries, they reflect two fundamentally different engineering philosophies:

• BS 6708 focuses on dimensional consistency and construction standardisation, making it ideal for quarrying and controlled mining environments.

• SANS 1520 represents a holistic, safety-driven mining cable system, engineered for extreme conditions and long-term reliability.

Choosing the correct standard is not merely a technical decision—it is a strategic investment in safety, compliance, and operational continuity.

In harsh mining environments, the right cable standard is as critical as the machinery it powers.

Contact Anhui Feichun Special Cable Co., Ltd.

For comprehensive technical specifications and quotations, please contact our specialized mining cable engineering team:

Technical Engineering Support:

tech@feichuncables.com

Sales Engineering Department:

Li.wang@feichuncables.com

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Manufacturer: Anhui Feichun Special Cable Co., Ltd. (安徽飞纯特种电缆有限公司)

Manufacturing Headquarters: Building A, Private Science and Technology Park, Hefei Economic and Technological Development Zone, Anhui Province, People’s Republic of China

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