(N)3GHSSHCH Flexible Mining & Tunnelling Cable

What is (N)3GHSSHCH Cable?

The (N)3GHSSHCH cable is a specialized medium-voltage, double-inner-sheathed, braided-armour flexible mining cable rated for 3.6/6kV, 6/10kV, 8.7/15kV, and 12/20kV electrical distribution systems, manufactured with Class 5 flexible copper conductors, high-grade rubber insulation, individual copper earth screens, a concentric copper monitoring conductor, a steel wire braid, and flame-retardant LSZH sheathing in accordance with VDE 0250 Part 605 and EN 60228 standards. It is engineered primarily to supply primary electrical energy to mobile and semi-mobile medium-voltage mining excavators, roadheaders, tunnel boring machines (TBMs), and underground substations.

Unlike standard industrial cables, underground mining and tunneling infrastructures require severe torsional resistance, continuous pilot and earth monitoring, and complete protection against electrical shock hazards caused by rockfall or mechanical impact. The (N)3GHSSHCH design incorporates individually screened power cores along with an integrated copper wire monitoring screen positioned between two LSZH inner sheaths, allowing earth-fault and pilot-monitoring relays to trip breakers instantly in the event of mechanical puncture. Furthermore, its zero-halogen formulation ensures that no toxic acid gases or visibility-impairing black smoke are emitted during fire emergencies in confined subterranean tunnels.

(N)3GHSSHCH Cable Construction

• Conductor: Class 5 flexible stranded plain annealed copper phase conductors conforming to VDE 0295 and EN 60228, providing high fatigue endurance under repeated dynamic bending.
• Insulation: High-dielectric elastomeric rubber compound engineered for flexible medium-voltage stress containment.
• Semi-Conductive Layers: Semi-conductive tape over the conductor, accompanied by extruded inner and outer semi-conductive rubber layers on the insulation for uniform electrical field control.
• Protective Earth Conductor: Individual copper wire screen applied over each insulated phase core for reliable fault current return.
• Control Conductor: Class 5 flexible stranded tinned copper control cores for signaling and pilot monitoring circuits.
• Central Filler: High-resilience rubber compound extruded over a high-tensile textile polyester support for structural core stability.
• Bedding / Inner Sheaths: First extruded Low Smoke Zero Halogen (LSZH) inner sheath, followed by a second LSZH inner sheath.
• Monitoring Conductor: Concentric copper wire screen applied over the first inner sheath to provide continuous ground-fault and insulation-integrity monitoring.
• Armour: Heavy-duty steel wire braid applied over the second inner sheath to deliver high tensile strength, torsion absorption, and crush protection.
• Outer Sheath: Robust, abrasion-resistant, and tear-resistant Low Smoke Zero Halogen (LSZH) compound.
• Core Identification: Phase cores with semi-conductive layers and individual copper screens; color-coded/numbered control cores.
• Sheath Colour: Black.

Applications

(N)3GHSSHCH medium-voltage flexible cables are specifically engineered for power distribution and mobile equipment interconnection across underground extraction shafts, subway transit tunnels, and civil infrastructure drilling projects. Their flame-retardant, zero-halogen, and mechanically reinforced architecture makes them suitable for both indoor tunnels and exposed outdoor quarry terrains.

• Underground Coal & Hard Rock Mining: Supplying medium-voltage electrical power to mobile shearers, continuous miners, underground conveyors, and mobile substations.
• Tunnel Boring & Civil Excavation: Flexible trailing leads and trailing feeder circuits powering Tunnel Boring Machines (TBMs), shotcrete units, and drilling rigs.
• Subterranean Confined Spaces: Installations along subway tubes, utility tunnels, and underground caverns where LSZH fire safety is strictly mandated.
• Surface Quarries & Open-Cast Mines: Heavy-duty dynamic power supply cables subject to continuous abrasion, mechanical dragging, and weather exposure.

Specifications & Dimensions

The (N)3GHSSHCH cable portfolio spans comprehensive medium-voltage ratings including 3.6/6kV (test voltage 11kV), 6/10kV (test voltage 17kV), 8.7/15kV (test voltage 24kV), and 12/20kV (test voltage 29kV), configured with 3 phase conductors, 3 split earth conductors, and 3 control/monitoring conductors (3+3+3+UL/OL). Phase conductor cross-sections range from 25mm² to 150mm² with conductor diameters from 6.1mm to 15.5mm, accommodating maximum tensile pulling forces up to 6,750 N. Operating temperatures span from -40°C to +80°C for fixed installations and +5°C to +80°C under dynamic flexing, maintaining a minimum bending radius of 6× overall diameter (fixed) and 10× overall diameter (flexed). Overall cable outer diameters range from 47.2mm on 3.6/6kV 25mm² up to 75.3mm on 12/20kV 120mm² constructions, with current-carrying capacities up to 428A on ground and multi-layer reeled ratings down to 29A, adhering strictly to VDE 0250 Part 605 and EN 60228 dimensional and electrical tolerances.

Standards

Design & Manufacturing Standards: VDE 0250 Part 605, VDE 0207, VDE 0295, EN 60228
Flame Retardancy: IEC/EN 60332-1-2 (Single vertical cable flame test)
Halogen-Free Performance: IEC/EN 60754-1/2 (Zero Halogen Acid Gas Emission)
Voltage Ratings (Uo/U): 3.6/6kV, 6/10kV, 8.7/15kV, 12/20kV
Testing Voltages: 3.6/6kV: 11kV; 6/10kV: 17kV; 8.7/15kV: 24kV; 12/20kV: 29kV
Temperature Spectrum: Fixed: -40°C to +80°C; Flexed: +5°C to +80°C
Bending Performance: Fixed: 6 × overall diameter; Flexed: 10 × overall diameter
Regulatory Compliance: RoHS Directive 2015/65/EU, REACH Directive EC 1907/2006

Frequently Asked Questions

Q: What is the specific function of the concentric copper wire monitoring screen in (N)3GHSSHCH cable?
A: The monitoring screen is situated over the first LSZH inner sheath and operates in conjunction with electrical monitoring relays; if outer mechanical crushing occurs, the monitoring circuit detects ground potential or insulation loss immediately, de-energizing the cable before phase puncture occurs.

Q: Why is an LSZH sheath specified rather than conventional polychloroprene (PCP) for underground mining?
A: Traditional rubber mining cables release corrosive hydrochloric acid gas and dense black smoke during fires; the LSZH formulation eliminates acid gas generation (per IEC/EN 60754-1/2) and minimizes smoke density, protecting personnel and delicate subterranean ventilation equipment.

Q: What mechanical protection does the steel wire braid armour provide?
A: The steel wire braid provides exceptional radial crush resistance against sharp falling rock fragments, absorbs high longitudinal tensile stresses up to 6,750 N during cable pulling, and prevents structural ovalization during reeled drum operations.

Q: What payment terms does Huadong Cable accept for international mining and tunnelling project orders?
A: We accept standard international commercial payment terms, including Telegraphic Transfer (T/T, with 30% advance deposit and 70% against shipping documents) and 100% Irrevocable Letter of Credit (L/C) at sight.

(N)3GHSSHCH Cable – Why Choose Huadong Cable?

Huadong Cable Group manufactures (N)3GHSSHCH medium-voltage flexible mining cables in strict compliance with VDE 0250 Part 605 and EN 60228 standards, verified through rigorous routine spark testing, partial discharge monitoring, high-voltage withstand tests (up to 29kV), and IEC/EN 60332-1-2 flame propagation assessments. Utilizing high-purity Class 5 flexible copper conductors, dual-layer semi-conductive vulcanized rubber screening, integrated monitoring screens, and high-tensile steel wire braiding, our automated continuous production lines ensure unmatched operational safety and dielectric durability under punishing subterranean mining environments.

With more than 20 years of precision cable manufacturing experience, Huadong Cable Group operates specialized multi-core cabling workshops, heavy-duty braiders, and material compounding facilities certified to ISO 9001 quality management protocols. By supplying direct from our manufacturing plant, mining contractors and tunneling infrastructure builders benefit from competitive factory pricing, 100% Mill Test Certificates (MTC) verifying electrical and mechanical ratings, customized continuous drum lengths packaged on ISPM 15 heat-treated export steel-reinforced wooden reels, and seamless door-to-port global logistics.