BS 6708 Type 3211900/3300V Armoured Mining & Trailing Cable for Excavating, Crushing, and Quarry Equipment with EPR Insulation and Heavy-Duty Chloroprene Sheath
APPLICATION：
Used for supplying excavating, crushing machines and equipment. Can also be used as trailing cable in quarries.
Cable Structure:
CONDUCTOR : Electrolytic, stranded, tinned copper wire IEC 60228 Class 5
INSULATION : EPR
LAYUP : All cores are laid up in contact with each other.
BEDDING : Rubber based bedding compound.
ARMOUR : Galvanized steel pliable armour.
OUTER SHEATH : Heavy duty chloroprene outer sheath.
Cable Properties:
RELATED STANDARDS : BS 6708
RATED VOLTAGE : 1900/3300 V
TEST VOLTAGE : 7.5 kV
Technical Specifications:
Cross Section | 4×35 | 4×50 | 4×70 | 4×95 | 4×120 | |
|---|---|---|---|---|---|---|
Conductors | ||||||
Number and cross section | mm2 | 4×35 | 4×50 | 4×70 | 4×95 | 4×120 |
Insulation thickness | mm | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 |
Cable details | ||||||
Radial thickness of inner sheath | mm | 2.5 | 3.8 | 3.8 | 5.0 | 5.0 |
Min. inner sheath diameter | mm | 40.8 | 47.7 | 52.8 | 60.3 | 63.9 |
Max. inner sheath diameter | mm | 43.3 | 50.2 | 55.8 | 63.3 | 66.9 |
Size of armour | mm | 7/0,90 | 7/0,90 | 7/0,90 | 7/1,25 | 7/1,25 |
Outer sheath thickness | mm | 5.0 | 5.4 | 5.9 | 6.4 | 6.8 |
Min. overall diameter | mm | 56.2 | 63.9 | 70.0 | 80.6 | 85.0 |
Max. overall diameter | mm | 60.0 | 67.7 | 74.0 | 84.9 | 89.3 |
Min. bending radius | mm | 720 | 813 | 888 | 1.019 | 1.072 |
Appx. cable weight | kg/km | 6.65 | 8.8 | 10.38 | 15.35 | 18.2 |
Copper weight | kg/km | 1.344 | 1.92 | 2.688 | 3.648 | 4.608 |
Electrical details | ||||||
“Continuous current | A | 135 | 170 | 205 | 250 | 295 |
Max. DC resistance at 20°C | ||||||
Phase conductors | Ω /km | 0.565 | 0.393 | 0.277 | 0.210 | 0.164 |
Armour | Ω /km | 1.0 | 0.8 | 0.53 | 0.40 | 0.32 |
What Is the BS 6708 Type 321 Mining Cable?
The BS 6708 Type 321 is an armoured mining cable designed for heavy-duty industrial environments. It features a stranded, tinned copper conductor, EPR insulation, and a heavy-duty chloroprene outer sheath. Rated at 1900/3300V with a test voltage of 7.5 kV, this cable ensures safe and reliable power transmission in mining, quarrying, and other rugged industrial applications.
Its versatility allows it to serve as a trailing cable, meaning it can be used to power mobile machinery in quarries without compromising safety or durability.
How Is the BS 6708 Type 321 Cable Constructed?
Understanding the cable's structure is key to appreciating its robustness:
Component | Description |
|---|---|
Conductor | Electrolytic, stranded, tinned copper wire (IEC 60228 Class 5) ensures flexibility and low electrical resistance. |
Insulation | Ethylene Propylene Rubber (EPR) provides excellent thermal stability, electrical insulation, and resistance to oils and chemicals. |
Layup | All cores are laid in contact, improving flexibility and current distribution. |
Bedding | Rubber-based bedding compound cushions the cores and provides an additional layer of mechanical protection. |
Armour | Galvanized steel pliable armour shields the cable against mechanical damage, abrasion, and crushing forces. |
Outer Sheath | Heavy-duty chloroprene sheath offers resistance to cuts, impact, oil, UV exposure, and harsh environmental conditions. |
This construction enables the cable to withstand mechanical stress from moving machinery, impact, and environmental factors, making it ideal for underground and surface mining operations.
How Does BS 6708 Type 321 Compare with Other Mining Cables?
When choosing a mining cable, engineers often compare Type 321 with other BS 6708 cables, such as Type 211 or Type 201. Key differentiators include:
Feature | BS 6708 Type 321 | BS 6708 Type 211 | BS 6708 Type 201 |
|---|---|---|---|
Rated Voltage | 1900/3300V | 640/1100V | 640/1100V |
Outer Sheath | Heavy-duty chloroprene | Chloroprene | Chloroprene |
Armour | Galvanized steel | Tinned copper screen | Tinned copper screen |
Application | Excavators, crushers, quarry trailing | Excavators, crushers | Excavators, crushers |
Mechanical Protection | High | Medium | Medium |
The higher voltage rating and robust armouring make Type 321 ideal for high-power equipment and trailing applications in quarries, where mechanical stress is significant.
What Are the Electrical Considerations When Using BS 6708 Type 321?
When installing and operating this cable, engineers should consider:
Continuous current rating – Ensure the selected cross-section matches the machine's load to avoid overheating.
Voltage drop – For long runs, check the voltage drop to maintain machine efficiency.
Bending radius – Follow minimum bending radius to prevent insulation and armour damage.
Temperature rating – EPR insulation provides excellent thermal tolerance, suitable for underground and surface mining conditions.
How Should BS 6708 Type 321 Be Installed?
Proper installation ensures safety and long service life:
Routing – Avoid sharp bends and high-tension points.
Bending radius – Always maintain the minimum bending radius (e.g., 720 mm for 4×35 mm²).
Mechanical protection – Use cable trays or clamps in areas with high abrasion.
Connection – Use compatible lugs and connectors for tinned copper conductors.
Inspection – Regularly inspect for sheath wear, armour damage, or overheating.
Why Choose BS 6708 Type 321 for Your Mining Operation?
High reliability – Maintains performance under extreme mechanical and electrical stress.
Safety compliance – Meets BS 6708 standards for mining cables.
Versatility – Suitable for excavators, crushers, and quarry trailing.
Durability – EPR insulation, heavy-duty chloroprene sheath, and steel armour extend cable life.
South African proven case studies – Reduced downtime and improved operational efficiency.
For mining operations requiring reliable, heavy-duty power cables, BS 6708 Type 321 is the industry-standard choice. Contact your supplier today to discuss the right cross-section and length for your machinery, ensuring safe and efficient operations in quarries and mines across South Africa.
