BS 6708 Type 307S Mining Cable – Heavy-Duty Screened 1.9/3.3kV Cable for Excavating & Crushing Machines with EPR Insulation and Chloroprene Sheath
APPLICATION:
Used for supplying excavating, crushing machines and equipment.
Cable Structure:
CONDUCTOR : Electrolytic, stranded, tinned copper wire IEC 60228 Class 5
INSULATION : EPR (Ground core is not insulated).
SEPERATOR : Colored Textile tape for core identification.
SCREEN : Tinned copper / Nylon braided screen over phase cores. Pilot core is not screened.
LAYUP : All cores are laid up in contact with the bare copper earth conductor.
BEDDING : Rubber based bedding compound.
OUTER SHEATH : Heavy duty chloroprene outer sheath.
Cable Properties:
RELATED STANDARDS : BS 6708
RATED VOLTAGE : 1,9/3,3 kV
TEST VOLTAGE : 7,5 kV – 2,5kV (Pilot conductors)
Technical Specifications:
Cross Section | 3×50+35+3×4 | 3×70+50+3×6 | 3×95+50+3×6 | 3×120+70+3×10 | |
|---|---|---|---|---|---|
Phase Conductor | |||||
Number and cross section | mm2 | 3×50 | 3×70 | 3×95 | 3×120 |
Insulation diameter | Nom. mm | 15.80 | 17.80 | 19.20 | 21.60 |
Screen diameter | Nom. mm | 18.20 | 20.15 | 21.60 | 23.95 |
Earth Conductor | |||||
Number and cross section | mm2 | 1×35 | 1×50 | 1×50 | 1×70 |
Stranding | mm | 276/0,40 | 396/0,40 | 396/0,40 | 360/0,50 |
Conductor diameter | Nom. mm | 8.20 | 9.80 | 9.80 | 11.70 |
Pilot Conductor | |||||
Number and cross section | mm2 | 3×4 | 3×6 | 3×6 | 3×10 |
Stranding | mm | 56/0,30 | 84/0,30 | 84/0,30 | 80/0,40 |
Conductor diameter | Nom. mm | 2.60 | 3.50 | 3.50 | 4.40 |
Insulation diameter | Nom. mm | 5.55 | 6.40 | 6.40 | 7.30 |
Diameter over sheath | Nom. mm | 17.80 | 19.80 | 21.20 | 23.60 |
Cable details | |||||
Min. overall diameter | mm | 56.8 | 62.8 | 68.9 | 73.4 |
Max. overall diameter | mm | 59.8 | 65.8 | 72.7 | 77.2 |
Min. bending radius | mm | 478 | 526 | 581 | 617 |
Max. pulling tension | kgf | 1.2 | 1.68 | 2 | 2 |
Appx. cable weight | kg/km | 5.85 | 7.15 | 8.6 | 10.5 |
Copper weight | kg/km | 2.685 | 3.319 | 4.039 | 4.951 |
Electrical details | |||||
“Continuous current | A | 170 | 205 | 250 | 295 |
“Intermittent current | A | 210 | 255 | 315 | 360 |
Max. DC resistance at 20°C | |||||
Phase Conductor | Ω /km | 0.393 | 0.277 | 0.21 | 0.164 |
Pilot Conductor | Ω /km | 5.09 | 3.39 | 3.39 | 1.95 |
3 screens and earth in | Ω /km | 0.35 | 0.35 | 0.28 | 0.28 |
Nom. reactance at 50Hz | Ω /km | 0.113 | 0.108 | 0.105 | 0.101 |
Nom. reactance at 60Hz | Ω /km | 0.136 | 0.129 | 0.126 | 0.121 |
Min. insulation | M Ω /km | 950 | 820 | 720 | 660 |
3 phase voltage drop on full load current | mV/A/m | 0.85 | 0.61 | 0.48 | 0.39 |
Mining operations are inherently challenging, demanding equipment that can endure harsh environments, heavy mechanical stress, and high electrical loads. One of the critical components ensuring safety and efficiency in mining is the mining cable. Among the various options available, the BS 6708 Type 307S mining cable stands out as a heavy-duty, screened, 1.9/3.3kV solution designed specifically for excavating and crushing machines. But what exactly makes it suitable for these applications, and how does it compare to other cables?
What Is the BS 6708 Type 307S Mining Cable?
The BS 6708 Type 307S is a high-performance, heavy-duty mining cable developed under the BS 6708 standard. It is designed to supply power to excavating, crushing, and other heavy mining machines, where reliability and safety are critical. The cable features EPR (Ethylene Propylene Rubber) insulation and a chloroprene outer sheath, combining flexibility, mechanical strength, and resistance to harsh mining conditions.
Key characteristics include:
Rated voltage: 1.9/3.3kV
Heavy-duty screened phase cores
Tinned copper conductors for corrosion resistance
Robust chloroprene outer sheath for mechanical and chemical protection
This combination of design features ensures the cable can withstand continuous mechanical stress, abrasive environments, and exposure to water or chemicals commonly found in mining operations.
How Does the BS 6708 Type 307S Perform Electrically?
The BS 6708 Type 307S is designed for both continuous and intermittent current ratings:
Continuous rating ranges from 170A to 295A, depending on cross-section.
Intermittent rating ranges from 210A to 360A.
Its low DC resistance ensures efficient power delivery with minimal voltage drop. The screened phase cores, combined with the bare copper earth conductor, also provide excellent fault protection and reduced electromagnetic interference—critical for maintaining machine reliability in heavy mining environments.
Where Is BS 6708 Type 307S Used in Mining Operations?
The BS 6708 Type 307S is primarily used for powering excavating and crushing machines, including:
Bucket wheel excavators
Jaw and cone crushers
Continuous miners
Conveyor drive units
Its heavy-duty construction allows it to operate in:
Underground tunnels
Open-pit mining operations
Harsh, abrasive, or wet conditions
South African Case Study
In South Africa, several platinum and gold mines have successfully deployed the BS 6708 Type 307S for underground crushing stations. Mine operators report:
Reduced downtime due to cable failures
Improved machine efficiency thanks to consistent voltage delivery
Extended cable lifespan, even under abrasive tunnel conditions
This real-world usage confirms the cable’s reliability in extreme mining environments.
How Does BS 6708 Type 307S Compare to Other Mining Cables?
Compared to other BS 6708 variants:
Feature | Type 307 | Type 307S | Type 307M |
|---|---|---|---|
Rated Voltage | 1.9/3.3 kV | 1.9/3.3 kV | 1.9/3.3 kV |
Screening | Optional | Screened | Screened |
Mechanical Protection | Moderate | Heavy-duty | Medium-duty |
Flexibility | High | Moderate | High |
Primary Use | Light excavation | Heavy excavation & crushing | Mobile equipment & feeders |
The Type 307S excels in heavy-duty mechanical and abrasive environments, making it ideal for high-load excavating and crushing machinery, whereas the Type 307 is more suited to lighter machinery, and Type 307M focuses on mobile equipment.
What Are the Installation Best Practices for BS 6708 Type 307S?
To maximize performance and safety:
Follow minimum bending radius: Avoid bending the cable below 10× its overall diameter.
Use proper cable supports: Ensure that heavy cables are supported to prevent mechanical strain.
Maintain clean connections: Ensure all terminations are correctly crimped and insulated.
Monitor for wear: Regular inspections for abrasion or sheath damage are recommended.
Avoid excessive pulling tension: Respect maximum pulling loads (1.2–2 tons depending on size) to prevent internal conductor damage.
Proper installation extends cable life and ensures uninterrupted mining operations.
Why Choose BS 6708 Type 307S for Your Mining Operation?
The BS 6708 Type 307S offers a compelling combination of:
Heavy-duty mechanical protection
High electrical performance
Durability under harsh mining conditions
Compliance with BS 6708 standards
By investing in the Type 307S, mine operators in South Africa and beyond can ensure reliable power supply, reduce downtime, and protect expensive mining equipment from electrical or mechanical failure.
Upgrade Your Mining Operations Today
For mining companies looking to enhance reliability and safety, the BS 6708 Type 307S is a proven solution. Contact a certified supplier today to:
Evaluate the correct cable size for your equipment
Get installation recommendations
Access local South African case studies for performance validation
Investing in the right cable ensures efficient, safe, and cost-effective mining operations.
