Type YUHKGXSekFpyn 3.6/6 kV Power cables

Fully shielded power cable for mining, tinned copper wire shielding layer, minimizes electromagnetic interference,

flame retardant cross-linked polyethylene insulation, polyvinyl chloride sheath, full shielding,

flat steel wire armor, longitudinal seal, flame retardant high-performance PVC sheath

Type YUHKGXSekFpyn 3.6/6 kV Power Cables – Enhanced for Mining Applications

The Type YUHKGXSekFpyn cable is a fully shielded power cable engineered specifically for underground mining. It is designed to offer superior electrical performance, enhanced electromagnetic interference (EMI) protection, and robust mechanical durability—all essential in harsh, hazardous mining environments.

Key Features and Construction:

• Fully Shielded Design:

  • Enhanced EMI Protection: A dedicated tinned copper wire shielding layer, combined with both individual conductor shields and an overall copper tape shield, minimizes EMI for stable operation.

• Conductor and Insulation:

  • Conductors: Round, multi-strand, compacted copper wires (Class 2 as per EN 60228) ensure excellent electrical conductivity and flexibility.

  • Insulation: Uses flame retardant cross-linked polyethylene (XLPE, Type DIX 3), which provides high thermal and electrical resistance.

• Upgraded Armor and Sealing:

  • Flat Steel Wire Armor: Upgraded from round steel wire armor (used in the Type YUHKGXSekFoyn cables), the flat steel wire armor improves mechanical strength and ease of installation—especially in steep or confined mine shafts.

  • Moisture Seal: A water-swelling, longitudinal sealing tape prevents moisture ingress, protecting the cable’s integrity.

  • Outer Sheath: A high-performance, flame retardant PVC (tire-grade) outer sheath offers improved flame resistance and durability according to IEC standards.

Differences and Improvements Over Type YUHKGXSekFoyn:

• Enhanced EMI Shielding:

  • The new design adds a dedicated tinned copper wire shielding layer, offering more effective EMI reduction than the previous version.

• Improved Mechanical Protection:

  • Switching from round to flat steel wire armor enhances the cable’s resistance to physical damage while also making it easier to install in challenging, inclined environments.

• Superior Flame Retardancy:

  • The upgraded outer sheath is made from high-performance, flame retardant PVC that better meets IEC 60332-1-2 and IEC 60332-3-24C standards, ensuring increased safety in explosive atmospheres.

Applications:

These cables are ideal for underground mining power distribution networks with a rated voltage up to 6 kV. They are suited for use in both non-methane and methane hazardous zones, ensuring safe and reliable operation even under severe conditions.

Standard and Certification

• Standard: Norma ZN-TF 203:2006

• Certifications: Approved by EMAG, WUG and compliant with RoHS75.

• Application: Designed for underground mining power distribution systems (≤6 kV) in both non-methane and methane hazardous areas, including installations in steep tunnels (above 45°).

Construction (BUDOWA)

1. Conductors:

   • Material & Structure:

     • Copper conductors that are round, multi-stranded, and compacted to Class 2 according to EN 60228.

   • Function:

     • Provides reliable current conduction and mechanical flexibility.

2. Individual Conductor Shielding:

   • Method:

     • Shielding applied on each conductor using conductive tape or polyethylene-based material.

   • Benefit:

     • Reduces electromagnetic interference (EMI) and improves overall signal quality.

3. Insulation:

   • Material:

     • Flame-retardant cross-linked polyethylene (XLPE) insulation, Type DIX 3 as per PN-HD 620 S1:2002.

   • Property:

     • Offers excellent thermal, electrical, and chemical resistance.

4. Individual Screen:

   • Design Options:

     • Either a wrap of conductive tape combined with copper tape or conductive polyethylene with copper tape.

   • Purpose:

     • Enhances EMI protection around each working conductor.

5. Conductor Core:

   • Structure:

     • The working conductors are twisted around a central core (using copper wire or strand) to maintain structural integrity.

6. Filling Layer:

   • Material:

     • Non-vulcanized rubber or tire-grade PVC (polywinit).

   • Role:

     • Ensures the cable retains its shape and offers additional mechanical protection.

7. Inner Sheath:

   • Material:

     • PVC (type DMV 31) in accordance with PN-HD 620 S1:2002.

   • Function:

     • Provides an extra layer of insulation and protection for internal components.

8. Overall Shielding:

   • Method:

     • A copper tape wrap is applied over the insulated conductors.

   • Advantage:

     • Offers full EMI protection across the entire cable.

9. Armor:

   • Type:

     • Flat steel wire armor.

   • Improvement:

     • Compared to the previous round wire design (in the Type YUHKGXSekFoyn cables), the flat armor offers enhanced mechanical protection and is easier to install in confined or steep environments.

10. Longitudinal Sealing:

    • Mechanism:

      • A water-swelling tape is used along the cable’s length.

    • Purpose:

      • Prevents moisture ingress, safeguarding the cable’s internal components.

11. Outer Sheath:

    • Material:

      • High-performance, flame-retardant PVC (tire-grade, type DMV 31) that meets IEC 60332-1-2 and IEC 60332-3-24C standards.

    • Function:

      • Provides robust protection against flames, mechanical damage, and environmental hazards.

Electrical and Mechanical Characteristics

• Insulation Color: Natural

• Sheath Color: Red

Temperature Ratings

• Maximum Conductor Operating Temperature: +90°C

• Minimum Ambient Temperature (permanent installation): -30°C

• Minimum Conductor Temperature During Installation (without heating): -50°C

• Maximum Conductor Temperature During Short Circuit: +250°C

Bending and Testing

• Minimum Bending Radius: 12 times the external cable diameter (12 x D)

• Test Voltage: 15 kV AC applied for 5 minutes at 50 Hz

Flame Propagation Resistance

• Standards: Meets IEC 60332-1-2 and IEC 60332-3-24C specifications

Mechanical Strength

• Maximum Pulling Force: 50 times the sum of the conductor cross-sectional areas (50 x S, with S in mm²)

Packaging

• Standard Packaging: Available in reels of 500 or 1000 meters, with custom lengths and packaging options available.

Cable Sizes and Specific Parameters

The cable is available in several sizes, for example: 3x25/25, 3x35/25, 3x50/25, 3x70/25, 3x95/30, 3x120/30, 3x150/30, and 3x185/30. For each size, the following parameters are defined:

1. Conductor Details:

   • Nominal Conductor Cross-Section: Ranges from 25 mm² up to 185 mm² per conductor.

   • Maximum Conductor Resistance at 20°C: Varies per size (e.g., 0.727 Ω/km for 3x25/25).

2. Insulation, Sheath, and Armor Thickness:

   • Insulation Thickness: Typically around 2.5 mm.

   • Sheath Thickness: Approximately 1.4 mm.

   • Armor Thickness: Ranges from 2.5 mm to 3.3 mm depending on the cable size.

3. Cable Diameter and Weight:

   • Approximate Cable Diameter: Starts at around 48.0 mm and increases with cable size.

   • Approximate Cable Weight: For example, a 3x25/25 cable weighs about 4156 kg/km, with heavier sizes scaling accordingly.

4. Electrical Performance for Working Conductors:

   • Current-Carrying Capacity: Specified for ambient temperature +25°C. For instance, a 25 mm² conductor supports 146 A, while larger conductors support higher currents.

   • Inductance: Typically ranges from 0.27 mH/km to 0.35 mH/km, decreasing slightly with increasing conductor size.

   • Inductive Reactance: Ranges from about 0.084 Ω/km to 0.111 Ω/km.

Installation Considerations

1. Parallel Installation Correction Factors:

   • When cables are installed in parallel (stacked on supports), current-carrying capacities must be adjusted:

     • 1 cable: 1.00

     • 2 cables: 0.93

     • 3 cables: 0.90

     • 6 cables: 0.87

     • 9 cables: 0.86

2. Ambient Temperature Correction Factors (for cables with a long-term permissible operating temperature of +90°C):

   • At 30°C: 0.96

   • At 35°C: 0.92

   • At 40°C: 0.88

   • At 45°C: 0.83

   • At 50°C: 0.78

   • At 55°C: 0.73