What is the AS/NZS 1802 Type 275 1.1 KV Mining Cable?

1. Introduction

Mining operations require specialized electrical equipment capable of withstanding extreme conditions. Among the critical components in these operations are mining cables, which must function reliably under mechanical stress, moisture exposure, and potential fire hazards. The AS/NZS 1802 Type 275 1.1 kV Mining Cable represents a specialized solution designed specifically for these challenging environments.

The Australian/New Zealand Standard 1802 (AS/NZS 1802) establishes requirements for reeling and trailing cables used in mining applications. The Type 275 1.1 kV cable is engineered to meet these stringent requirements while providing reliable power transmission in some of the world's harshest working conditions.

2. Application Scenarios

The AS/NZS 1802 Type 275 1.1 kV Mining Cable finds extensive use in various mining operations:

Underground Mining Operations

In underground coal mines and hard rock mining, these cables power machinery operating in confined spaces with constant exposure to dust, moisture, and abrasion risks.

Surface Mining and Open-Cut Mining Sites

At surface operations, these cables connect to mobile equipment while enduring exposure to weather elements, UV radiation, and temperature variations.

Tunneling and Heavy Industrial Environments

Beyond traditional mining, these cables are suitable for tunneling operations and heavy industrial settings where durability and reliability are paramount.

Suitable Machinery and Equipment

The Type 275 cable specifically serves as a flexible feeder for:

• Shuttle cars

• Mining pumps

• Continuous miners

• Other mobile mining equipment requiring reliable power supply

Harsh Environmental Conditions

These cables are engineered to withstand:

• Severe mechanical stress from dragging and reeling

• Regular exposure to water and moisture

• Potential flame risks inherent in mining operations

• Chemical exposure from mining processes

• Extreme temperature variations

3. Electrical and Mechanical Parameters

Voltage Rating

• Operating voltage: 1.1 kV

• The balanced 1.1/1.1kV rating indicates both phase-to-phase and phase-to-ground insulation protection

Conductor

• Flexible stranded tinned annealed copper conductor

• Available in various cross-sectional areas: 16mm², 25mm², 35mm², and 50mm²

• Strand configurations ranging from 126/0.40mm for 16mm² up to 380/0.40mm for 50mm²

• The tinning provides enhanced corrosion resistance in humid mining environments

Insulation Material

• Ethylene Propylene Rubber (EPR)

• Thickness: 1.6mm for smaller conductors, 1.7mm for 50mm² conductor

• EPR provides excellent electrical properties, flexibility, and temperature resistance

Earth Conductors

• Three interstitial earth conductors with semiconductive PCP covering

• Flexible stranded tinned copper construction

• Specifically designed to reduce instances of wire breaks during reeling under tension

• Sizes range from 60/0.30mm for 16mm² cable to 99/0.40mm for 50mm² cable

Pilot Conductor

• One central extensible pilot with EPR covering

• Flexible stranded tinned copper construction

• Sizes range from 24/0.20mm for smaller cables to 40/0.20mm for 50mm² cable

• Allows for monitoring of cable integrity and safety circuit implementation

Sheath Material

• Heavy-duty Polychloroprene (PCP) sheath

• Heavy-duty CPE/CSP (Chlorinated Polyethylene/Chlorosulfonated Polyethylene) sheath available upon request

• Thickness including semiconductive PCP layer: 3.8mm to 4.7mm depending on cable size

• Provides robust mechanical protection and flame resistance

Additional Construction Features

• Cradle separator made of semiconductive PCP

• Overall core screen with semiconductive PCP filling and covering

• Textile reinforcement with open-weave braid for enhanced mechanical strength

Temperature Range

• Typical operating range: -25°C to +90°C

Flexibility

• Designed for frequent movement, bending, and reeling operations

• Enhanced flexibility compared to standard industrial cables

Standards Compliance

• AS/NZS 1802:2003 – Australian/New Zealand Standard for reeling and trailing cables

• AS/NZS 1125 – Conductors in insulated electric cables and flexible cords

• AS/NZS 3808 – Insulating and sheathing materials for electric cables

• AS/NZS 5000.1 – Electric cables—Polymeric insulated

Physical Dimensions and Weight

• Nominal overall diameter: 30.2mm (16mm²) to 41.6mm (50mm²)

• Nominal weight: 145 kg/100m (16mm²) to 333 kg/100m (50mm²)

4. Frequently Asked Questions (FAQ)

Q1: Why can't we use regular industrial cables in mining?

A1: Regular industrial cables lack the specialized features needed for mining environments. The AS/NZS 1802 Type 275 cable offers superior mechanical strength to withstand dragging and crushing, enhanced flame resistance critical in combustible environments, greater flexibility for frequent movement, and specific design elements like interstitial earth conductors and extensible pilot wires. Regular cables would quickly fail under these extreme conditions, posing safety risks and causing expensive downtime.

Q2: How does the 1.1 kV rating affect performance underground?

A2: The 1.1 kV rating provides an optimal balance for medium-power mining applications. It delivers sufficient voltage for powering equipment like shuttle cars and pumps while maintaining reasonable insulation thickness and cable flexibility. This rating includes safety margins to account for voltage spikes and ensures reliable operation in damp underground conditions where electrical stresses can be higher.

Q3: What risks does the Type 275 cable help mitigate?

A3: The Type 275 cable mitigates several critical risks:

• Mechanical abrasion through its heavy-duty outer sheath and textile reinforcement

• Crushing damage from heavy machinery with its robust construction

• Fire propagation with flame-retardant materials

• Moisture ingress due to high-quality sheathing and insulation

• Electrical faults through proper screening and insulation

• Earth leakage issues with dedicated earth conductors

• Cable integrity failures through pilot wire monitoring capabilities

Q4: Can the Type 275 cable be repaired underground if damaged?

A4: Yes, with appropriate joint kits and trained technicians, the Type 275 cable can be repaired underground. However, these repairs should be performed according to strict guidelines to maintain cable integrity. The robust design of the cable aims to minimize damage in the first place, as repairs always represent a potential weak point. Regular inspection and preventive maintenance help identify potential issues before failure occurs.

Q5: What maintenance checks are recommended for mining cables?

A5: Recommended maintenance checks include:

• Visual inspections for cuts, abrasions, or burns on the outer sheath

• Checking for any exposed conductors or damaged insulation

• Electrical testing for insulation resistance and continuity

• Monitoring pilot wire integrity as an early warning system

• Megger testing at regular intervals to detect insulation degradation

• Documentation of cable history and past repairs

• Verification of proper strain relief at connection points

• Assessment of cable flexibility and signs of hardening or brittleness

5. Conclusion

The AS/NZS 1802 Type 275 1.1 kV Mining Cable represents a specialized engineering solution for the unique challenges of mining environments. Its robust construction featuring flexible tinned copper conductors, EPR insulation, interstitial earth conductors, central extensible pilot, and heavy-duty sheathing ensures reliable performance under extreme conditions.

For mining operations where safety and continuity are paramount, selecting compliant, high-quality cables like the Type 275 is not merely a regulatory requirement but a critical operational decision. The additional investment in proper mining-grade cables pays dividends through reduced downtime, lower maintenance costs, and—most importantly—enhanced safety for mining personnel working in these challenging environments.

When planning mining projects or upgrading existing facilities, always consult with specialists familiar with local regulations and specific site conditions to ensure the selection of appropriate cable types and configuration