{"id":11856,"date":"2026-05-12T10:06:12","date_gmt":"2026-05-12T02:06:12","guid":{"rendered":"https:\/\/feichuncables.com\/blog\/?p=11856"},"modified":"2026-05-12T10:31:26","modified_gmt":"2026-05-12T02:31:26","slug":"flexidrum-medium-r-901-3","status":"publish","type":"post","link":"https:\/\/feichuncables.com\/blog\/flexidrum-medium-r-901-3\/","title":{"rendered":"FLEXIDRUM\u00ae MEDIUM R 901"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">From 8,7\/15 Kv up to 12\/20 Kv<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img data-dominant-color=\"ece8e8\" data-has-transparency=\"false\" style=\"--dominant-color: #ece8e8;\" loading=\"lazy\" decoding=\"async\" width=\"1020\" height=\"628\" sizes=\"auto, (max-width: 1020px) 100vw, 1020px\" src=\"https:\/\/feichuncables.com\/blog\/wp-content\/uploads\/image-1425-1020x628.avif\" alt=\"\" class=\"wp-image-11858 not-transparent\" title=\"\" srcset=\"https:\/\/feichuncables.com\/blog\/wp-content\/uploads\/image-1425-1020x628.avif 1020w, https:\/\/feichuncables.com\/blog\/wp-content\/uploads\/image-1425-300x185.avif 300w, https:\/\/feichuncables.com\/blog\/wp-content\/uploads\/image-1425-768x473.avif 768w, https:\/\/feichuncables.com\/blog\/wp-content\/uploads\/image-1425-400x246.avif 400w, https:\/\/feichuncables.com\/blog\/wp-content\/uploads\/image-1425-800x492.avif 800w, https:\/\/feichuncables.com\/blog\/wp-content\/uploads\/image-1425-832x512.avif 832w, https:\/\/feichuncables.com\/blog\/wp-content\/uploads\/image-1425-1248x768.avif 1248w, https:\/\/feichuncables.com\/blog\/wp-content\/uploads\/image-1425.avif 1251w\" \/><\/figure>\n\n\n\n<!DOCTYPE html>\n<html lang=\"en\">\n<head>\n    <meta charset=\"UTF-8\">\n    <meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\">\n    <meta name=\"description\" content=\"FLEXIDRUM\u00ae MEDIUM R 901: Single-core high-voltage cable for tunnel boring machines with red copper braid screen, EPR insulation, dual voltage ratings (8.7\/15 kV to 12\/20 kV). -50 to +80\u00b0C fixed\/-30 to +80\u00b0C flexible, extreme tunneling environment resistance: mud abrasion, coolant oil, high-pressure water, saturation moisture. Class 5 red copper conductors. 14 complete SKU configurations across 2 series variants (SRL\/URL). Complete technical specifications, single-core MV physics, and TBM system engineering.\">\n    <meta name=\"keywords\" content=\"FLEXIDRUM R901, tunnel boring machine cable, TBM cable, single-core cable, high-voltage, red copper braid, 8.7\/15kV, 12\/20kV, EPR insulation\">\n    <meta property=\"og:title\" content=\"FLEXIDRUM\u00ae MEDIUM R 901 Tunnel Boring Machine Cable - FeiChun Technical Specification\">\n    <meta property=\"og:description\" content=\"Specialized single-core MV cable for tunnel boring machines with red copper braid screen, extreme environment protection. 8.7\/15 kV to 12\/20 kV, -50 to +80\u00b0C, mud\/coolant\/water resistant.\">\n    <meta property=\"og:type\" content=\"article\">\n    <meta name=\"canonical\" content=\"https:\/\/www.feichuncables.com\/products\/flexidrum-medium-r901\">\n    <title>FLEXIDRUM\u00ae MEDIUM R 901 Tunnel Boring Machine Cable | FeiChun Special Cables<\/title>\n    <style>\n        :root {\n            --primary-color: #1a3a52;\n      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   \"description\": \"Single-core high-voltage cable for tunnel boring machines with red copper braid screen, EPR insulation, dual voltage ratings (8.7\/15 kV to 12\/20 kV). -50 to +80\u00b0C fixed\/-30 to +80\u00b0C flexible, extreme tunneling environment protection. 14 complete SKU configurations across 2 series variants. Advanced single-core MV physics and TBM system engineering.\",\n        \"image\": \"https:\/\/www.feichuncables.com\/products\/flexidrum-medium-r901\/hero.jpg\",\n        \"author\": {\n            \"@type\": \"Organization\",\n            \"name\": \"Anhui Feichun Special Cable Co., Ltd.\",\n            \"url\": \"https:\/\/www.feichuncables.com\"\n        },\n        \"datePublished\": \"2026-05-11\",\n        \"dateModified\": \"2026-05-11\",\n        \"mainEntity\": {\n            \"@type\": \"Product\",\n            \"name\": \"FLEXIDRUM\u00ae MEDIUM R 901 Tunnel Boring Machine Cable\",\n            \"description\": \"Specialized single-core high-voltage cable for tunnel boring machines with red copper braid screen and extreme environment protection\",\n            \"brand\": {\n                \"@type\": \"Brand\",\n                \"name\": \"FeiChun\"\n            },\n            \"manufacturer\": {\n                \"@type\": \"Organization\",\n                \"name\": \"Anhui Feichun Special Cable Co., Ltd.\"\n            }\n        }\n    }\n    <\/script>\n\n    <!-- HEADER -->\n    <div class=\"doc-header\">\n        <div class=\"container\">\n            <div class=\"doc-header-badge\">Tunnel Boring Machine Cable<\/div>\n            <h1>FLEXIDRUM<sup>\u00ae<\/sup> MEDIUM R 901<\/h1>\n            <p>Single-Core High-Voltage Cable for Underground Tunneling Applications<\/p>\n            <div class=\"doc-meta\">\n                <span>\u26a1 Voltage: 8.7\/15 kV to 12\/20 kV<\/span>\n                <span>\ud83d\udd34 Screen: Red copper braid<\/span>\n                <span>\ud83c\udf21\ufe0f Temp: \u221250 to +80\u00b0C (extreme)<\/span>\n                <span>\u2699\ufe0f Application: TBM tunneling machines<\/span>\n            <\/div>\n        <\/div>\n    <\/div>\n\n    <!-- KEY SPECIFICATIONS GRID -->\n    <div class=\"container\">\n        <div class=\"spec-grid\">\n            <div class=\"spec-card\">\n                <div class=\"spec-card-label\">Nominal Voltage<\/div>\n                <div class=\"spec-card-value\">8.7\/15 kV<\/div>\n                <div class=\"spec-card-unit\">Up to 12\/20 kV available<\/div>\n            <\/div>\n            <div class=\"spec-card\">\n                <div class=\"spec-card-label\">Conductor Type<\/div>\n                <div class=\"spec-card-value\">Single-Core<\/div>\n                <div class=\"spec-card-unit\">1\u00d725 to 1\u00d7150 mm\u00b2 (red copper)<\/div>\n            <\/div>\n            <div class=\"spec-card\">\n                <div class=\"spec-card-label\">Screen<\/div>\n                <div class=\"spec-card-value\">Red Copper Braid<\/div>\n                <div class=\"spec-card-unit\">Conductive, corrosion-resistant grounding<\/div>\n            <\/div>\n            <div class=\"spec-card\">\n                <div class=\"spec-card-label\">Max Speed<\/div>\n                <div class=\"spec-card-value\">60 m\/min<\/div>\n                <div class=\"spec-card-unit\">Moderate-speed reel dragging<\/div>\n            <\/div>\n            <div class=\"spec-card\">\n                <div class=\"spec-card-label\">Operating Temp<\/div>\n                <div class=\"spec-card-value\">\u221250 to +80\u00b0C<\/div>\n                <div class=\"spec-card-unit\">Flexible: \u221230\u00b0C (thermal shielding)<\/div>\n            <\/div>\n            <div class=\"spec-card\">\n                <div class=\"spec-card-label\">Tensile Strength<\/div>\n                <div class=\"spec-card-value\">\u226420 N\/mm\u00b2<\/div>\n                <div class=\"spec-card-unit\">Designed for tunnel flexibility<\/div>\n            <\/div>\n        <\/div>\n\n        <!-- TABLE OF CONTENTS -->\n        <div class=\"toc-section\">\n            <h3>Contents<\/h3>\n            <ol class=\"toc-list\">\n                <li><a href=\"#section-1\">Single-Core MV Cable Design Theory &#038; Electrical Architecture<\/a><\/li>\n                <li><a href=\"#section-2\">Red Copper Braid Screen: Conductivity, Corrosion Resistance &#038; Thermal Pathways<\/a><\/li>\n                <li><a href=\"#section-3\">Grounding &#038; Shielding Effectiveness in Tunnel Excavation Environments<\/a><\/li>\n                <li><a href=\"#section-4\">Tunnel Boring Machine System Integration: Electrical &#038; Mechanical Design<\/a><\/li>\n                <li><a href=\"#section-5\">Mud-Cable Abrasion Mechanism &#038; Wear Physics in TBM Operation<\/a><\/li>\n                <li><a href=\"#section-6\">Coolant &#038; Hydraulic Oil Compatibility: Chemical Attack &#038; Swelling Analysis<\/a><\/li>\n                <li><a href=\"#section-7\">Moisture Saturation &#038; Water-Tree Acceleration in Saturated Tunnel Conditions<\/a><\/li>\n                <li><a href=\"#section-8\">SRL vs. URL Series Variants: Engineering Differentiation Strategy<\/a><\/li>\n                <li><a href=\"#section-9\">Complete SKU Catalog: 14 Configurations (2 Series \u00d7 7 Sizes)<\/a><\/li>\n                <li><a href=\"#section-10\">Comparative Analysis: R 901 (Single-Core) vs. R 902 (Three-Core) vs. Mining Applications<\/a><\/li>\n            <\/ol>\n        <\/div>\n\n        <!-- SECTION 1 -->\n        <h2 id=\"section-1\">1. Single-Core MV Cable Design Theory &#038; Electrical Architecture<\/h2>\n\n        <p>\n            FLEXIDRUM\u00ae MEDIUM R 901 represents a fundamentally different design paradigm from the <strong>three-core balanced systems<\/strong> (R 902 for mining). Single-core MV cables are used in TBM applications where <strong>three separate single-core cables<\/strong> (one per phase) are routed through the tunnel, providing advantages in flexibility and independent grounding.\n        <\/p>\n\n        <h3>1.1 Single-Core vs. Three-Core Architecture<\/h3>\n\n        <div class=\"formula\">\nThree-Core System (R 902 for mining):\n  Configuration: 3 power cores + 3 earth cores, all in single outer sheath\n  Magnetic field confinement: All three phases contained within one cable\n  Loop inductance: Low (fields cancel, balanced system)\n  EMI coupling: Phases couple to each other; earth potential uniform\n  Advantage: Compact, single reel, reduced outer diameter\n  Disadvantage: Unbalanced loading creates circulating currents; phase imbalance \u2192 asymmetric heating\n  Cost: Lower (one cable vs. three)\n\nSingle-Core System (R 901 for TBM):\n  Configuration: 1 power core + external red copper screen (shared among all 3 phases)\n  Typical deployment: 3 separate R 901 cables run parallel through tunnel\n  Magnetic field confinement: Each phase creates independent azimuthal field around its conductor\n  Loop inductance: Higher per phase (no flux cancellation from other phases nearby)\n  EMI coupling: Minimal between phases if properly spaced; shared screen provides common return path\n  Advantage: Extreme flexibility, independent phase routing, easy to add\/remove phases\n  Disadvantage: Three times the reel diameter (for equal total ampacity), weight, cost\n  Cost: Higher per unit (but economical when flexibility is critical)\n\nTunnel Boring Application Fit:\n  TBM excavation face is 100\u2013300 m away from surface power station\n  Power must be continuously supplied as machine advances (incremental jumps)\n  Single cables allow:\n    &#8211; Route around obstacles without re-configuring three-phase bundle\n    &#8211; Replace damaged single phase without stopping all three\n    &#8211; Gradually extend tunnel with repeated reel movements (pay out 50 m, advance machine, re-spool)\n        <\/div>\n\n        <h3>1.2 Return Path Architecture in Single-Core Design<\/h3>\n\n        <p>\n            The critical difference in single-core design is the <strong>return path<\/strong> for current. In three-core systems, return current flows through dedicated earth conductors. In single-core systems:\n        <\/p>\n\n        <div class=\"formula\">\nCurrent Path in R 901 Single-Core Cable:\n\nForward path (to TBM):\n  Current flows through central conductor (1\u00d725\u2013150 mm\u00b2 red copper)\n  Outward magnetic field generated: \u03a6 = (\u00b5\u2080 \u00d7 I) \/ (2\u03c0r)\n  Field strength at screen: B \u2248 (4\u03c0 \u00d7 10\u207b\u2077 \u00d7 I) \/ (2\u03c0r_screen) [Tesla]\n\nReturn path (from TBM back to substation):\n  Option 1: Via the RED COPPER SCREEN (integrated return conductor)\n    Screen carries equal and opposite current \u2212I\n    Magnetic fields cancel in far field (dipole configuration)\n    Screen carries full load current (in practice, ~100% of forward current)\n    \n  Option 2: Via earth return through tunnel\/rock formation\n    Some current leaks into surrounding earth at machine end\n    Return path distributed through conductive rock\/soil\n    Problematic: Earth is heterogeneous, creates circulating currents, losses\n    \nFLEXIDRUM\u00ae R 901 Design:\n  The RED COPPER BRAID SCREEN is the engineered return path (not incidental)\n  Screen conductivity: ~58 S\/m (excellent, nearly as good as solid copper)\n  Screen effective cross-section: Braid weave ~70\u201385% coverage\n  Effective conductance: ~0.7\u20130.85 \u00d7 solid copper conductor at same cross-section\n  \nLoop inductance (conductor + return via screen):\n  L = (\u00b5\u2080 \/ (2\u03c0)) \u00d7 ln(r_screen \/ r_conductor)\n  For R 901 1\u00d750 mm\u00b2: r_conductor \u2248 4 mm, r_screen \u2248 10 mm\n  L \u2248 (4\u03c0 \u00d7 10\u207b\u2077 \/ (2\u03c0)) \u00d7 ln(10\/4) \u2248 72 nH\/m (low, good for AC power quality)\n        <\/div>\n\n        <!-- SECTION 2 -->\n        <h2 id=\"section-2\">2. Red Copper Braid Screen: Conductivity, Corrosion Resistance &#038; Thermal Pathways<\/h2>\n\n        <h3>2.1 Why Red Copper vs. Alternatives<\/h3>\n\n        <p>\n            FLEXIDRUM\u00ae R 901&#8217;s specification of <strong>red copper braid screen<\/strong> (vs. standard iron\/steel braid or aluminum) is a critical engineering choice for tunneling:\n        <\/p>\n\n        <div class=\"formula\">\nBraid Material Comparison for Screen:\n\nIron\/Steel Braid (Traditional):\n  Conductivity: 10 S\/m (one-sixth of copper)\n  Corrosion resistance: POOR (rust formation in wet tunnel)\n  Corrosion mechanism: 4Fe + 3O\u2082 + 6H\u2082O \u2192 4Fe(OH)\u2083 (voluminous rust)\n  Rust volume: 2\u20133\u00d7 original iron volume \u2192 mechanical stress on insulation\n  Field life (tunnel): 3\u20135 years before braid integrity compromised\n  Advantage: Cheap, familiar\n  \nAluminum Braid:\n  Conductivity: 38 S\/m (two-thirds of copper)\n  Corrosion resistance: Moderate (Al\u2082O\u2083 passivation layer protects)\n  BUT: Galvanic corrosion when in contact with copper conductors\n  Galvanic cell: Cu is cathode (reduction), Al is anode (oxidation)\n  In saline tunnel water: Galvanic current flows, Al corrodes 100\u00d7 faster\n  Field life (tunnel): 2\u20133 years (worse than iron due to galvanic attack)\n  \nRed Copper Braid:\n  Conductivity: 58 S\/m (BEST, reference standard)\n  Corrosion resistance: Excellent in tunnel water\n  Copper corrosion: Cu + H\u2082O + O\u2082 \u2192 Cu(OH)\u2082 (adherent film, self-protective)\n  Cu(OH)\u2082 forms blue-green patina: This actually PROTECTS underlying copper\n  Galvanic effects: Copper is noble metal, doesn&#8217;t corrode when paired with steel\/aluminum\n  Field life (tunnel): 15\u201325 years (routinely)\n  \nCost trade-off:\n  Iron: \u20ac0.50\u20131.00\/meter\n  Aluminum: \u20ac1.50\u20132.50\/meter  \n  Red copper: \u20ac8\u201312\/meter (BUT lasts 5\u201310\u00d7 longer, economical over project life)\n        <\/div>\n\n        <h3>2.2 Thermal Properties of Red Copper Braid<\/h3>\n\n        <p>\n            Beyond electrical conductivity, red copper serves as a <strong>thermal highway<\/strong> in the cable:\n        <\/p>\n\n        <div class=\"formula\">\nThermal Conductivity Comparison:\n\nIron\/Steel: \u03ba \u2248 50 W\/(m\u00b7K)\nAluminum: \u03ba \u2248 160 W\/(m\u00b7K)\nRed copper: \u03ba \u2248 390 W\/(m\u00b7K) (BEST, ~7.8\u00d7 better than iron)\n\nHeat path in single-core cable:\n  Heat generated in conductor: P = I\u00b2R_conductor\n  Heat flows radially outward through:\n    (1) Inner insulation (EPR): \u03ba \u2248 0.25 W\/(m\u00b7K) (very low, insulating)\n    (2) Red copper screen: \u03ba \u2248 390 W\/(m\u00b7K) (EXCELLENT conductor of heat)\n    (3) Outer sheath (PUR): \u03ba \u2248 0.25 W\/(m\u00b7K)\n    (4) Tunnel air: \u03ba \u2248 0.026 W\/(m\u00b7K) (convection dominates)\n\nEffective heat dissipation via screen:\n  The copper braid carries ~70\u201385% of radial heat flow\n  This reduces peak conductor temperature by ~15\u201325\u00b0C vs. non-screened cable\n  \nExample: 1\u00d7150 mm\u00b2 cable, 300 A current, 60 m\/min reel speed\n  I\u00b2R conductor loss: (300)\u00b2 \u00d7 0.00011 \u03a9\/m \u2248 10 W\/m\n  Without copper screen, conductor temp rise: \u0394T \u2248 35\u201345\u00b0C (over-limit)\n  With copper screen, conductor temp rise: \u0394T \u2248 20\u201325\u00b0C (acceptable)\n  \nThis thermal advantage is NOT incidental\u2014it&#8217;s engineered into the design.\n        <\/div>\n\n        <!-- SECTION 3 -->\n        <h2 id=\"section-3\">3. Grounding &#038; Shielding Effectiveness in Tunnel Excavation Environments<\/h2>\n\n        <h3>3.1 Electromagnetic Compatibility in Tunnel Power Systems<\/h3>\n\n        <p>\n            TBM excavation creates significant <strong>electromagnetic noise sources<\/strong>:\n        <\/p>\n\n        <ul style=\"margin-left: 20px; margin-bottom: 16px;\">\n            <li><strong>Motor commutation:<\/strong> Brushed DC motors or PWM VFDs create broadband EMI (10 kHz\u2013100 MHz).<\/li>\n            <li><strong>Hydraulic solenoid valves:<\/strong> Rapid on\/off switching generates fast transients (di\/dt > 100 A\/\u00b5s).<\/li>\n            <li><strong>Welding power supplies:<\/strong> Often used on-site for tunnel support; highly EMI-emissive.<\/li>\n            <li><strong>Communication systems:<\/strong> Radio repeaters, signal cables vulnerable to interference.<\/li>\n        <\/ul>\n\n        <p>\n            The red copper braid screen provides dual EMI mitigation:\n        <\/p>\n\n        <div class=\"formula\">\nEMI Shielding Mechanism (Faraday Cage):\n\nCopper braid coverage: 70\u201385% (weave pattern)\nEffective coverage: With stranding\/braiding geometry, ~90%+ EMI attenuation\n\nShielding effectiveness: SE = 20 log\u2081\u2080(E_incident \/ E_transmitted) [dB]\n\nFor 1\u00d750 mm\u00b2 cable with red copper braid:\n  @ 10 kHz: SE \u2248 60\u201370 dB (excellent)\n  @ 100 kHz: SE \u2248 70\u201380 dB\n  @ 1 MHz: SE \u2248 80\u201390 dB\n  @ 10 MHz: SE \u2248 90\u2013100 dB\n  \nTranslation: 60 dB means 99.9% attenuation\n            70 dB means 99.99% attenuation\n            90 dB means 99.9999% attenuation\n\nGrounding Path:\n  The screen must be grounded at BOTH ENDS (source and load)\n  This creates a low-impedance return path for any induced currents\n  Voltage differential across screen: <1 V (keeps potentials balanced)\n  \nTwo-point grounding:\n  Substation end: Screen bonded to main earth electrode (typically <0.1 \u03a9)\n  TBM end: Screen bonded to machine chassis + earth stake at excavation\n  Bond wire: Large cross-section (#2 AWG minimum, ~34 mm\u00b2 Cu)\n        <\/div>\n\n        <!-- SECTION 4 -->\n        <h2 id=\"section-4\">4. Tunnel Boring Machine System Integration: Electrical &#038; Mechanical Design<\/h2>\n\n        <h3>4.1 Typical TBM Electrical Architecture<\/h3>\n\n        <p>\n            FLEXIDRUM\u00ae R 901 connects the surface substation (8.7 kV or 15 kV typically) to the TBM at depth:\n        <\/p>\n\n        <div class=\"formula\">\nSurface-to-TBM Power Distribution:\n\nSurface substation: 8.7 kV or 15 kV, three-phase 50\u201360 Hz\nThree cables routed separately through tunnel:\n  Cable 1 (Red phase): FLEXIDRUM\u00ae R 901, 1\u00d750\u2013150 mm\u00b2 (depending on machine size)\n  Cable 2 (Yellow phase): Identical\n  Cable 3 (Blue phase): Identical\n  Return path: Via red copper screens all bonded to common ground\n\nTunnel routing:\n  Cables run along tunnel wall, supported on cable trays every 5\u201310 m\n  Cables dragged incrementally as TBM advances (~20\u201350 m per shift)\n  Cable bundles wrapped with protective sleeve where resting on sharp rock edges\n\nTBM electrical loads:\n  Main drive motor(s): 500\u20132,000 kW (60\u2013150 A per phase at 8.7 kV)\n  Hydraulic pump motors: 100\u2013500 kW\n  Lighting, controls, ventilation: ~50\u2013100 kW\n  Total demand: 1\u20132.5 MW typical (120\u2013200 A per phase)\n\nCable sizing:\n  For 150 A per phase, 1\u00d7150 mm\u00b2 conductor provides:\n    Ampacity at 80\u00b0C: ~180\u2013200 A (acceptable margin)\n    Voltage drop @ 150 A: \u0394V = \u03c1 \u00d7 L \u00d7 I \/ A = 0.0000017 \u03a9\u00b7mm\u00b2\/mm \u00d7 200 m \u00d7 150 A \/ 150 mm\u00b2\n                         \u2248 0.34 V = 0.34 kV (acceptable <5% for MV)\n        <\/div>\n\n        <h3>4.2 Cable Reel System for TBM Deployment<\/h3>\n\n        <p>\n            Unlike fixed mining applications, TBM cables must be <strong>continuously managed on reels<\/strong> as the machine advances:\n        <\/p>\n\n        <ul style=\"margin-left: 20px; margin-bottom: 16px;\">\n            <li><strong>Reel capacity:<\/strong> Typically 500\u20132,000 m per reel (larger machines require longer reach).<\/li>\n            <li><strong>Reel speed:<\/strong> 60 m\/min is conservative for TBM (allows careful deployment, prevents kinks).<\/li>\n            <li><strong>Bending radius:<\/strong> Min 10\u00d7D fixed, 12\u00d7D for repeated winding (DIN VDE 0298).<\/li>\n            <li><strong>Weight management:<\/strong> Three 1\u00d7150 mm\u00b2 cables weigh ~6.7 kg\/m total, so 1 km per phase \u2248 6.7 metric tons\u2014requires heavy-duty reel apparatus.<\/li>\n        <\/ul>\n\n        <!-- SECTION 5 -->\n        <h2 id=\"section-5\">5. Mud-Cable Abrasion Mechanism &#038; Wear Physics in TBM Operation<\/h2>\n\n        <h3>5.1 Tunnel Mud Abrasion Physics<\/h3>\n\n        <p>\n            TBM excavation in soft ground produces <strong>mud slurry<\/strong> containing clay, silt, sand, and rock particles. Cables dragged through this slurry experience severe abrasion:\n        <\/p>\n\n        <div class=\"formula\">\nArchard Abrasion Model:\n\nVolume lost to wear: V = k \u00d7 N \u00d7 d \/ H\n  where: k = dimensionless wear coefficient (material pair dependent)\n         N = normal force (cable weight + tension)\n         d = sliding distance\n         H = hardness of softer material (cable sheath)\n\nFor TBM tunnel mud-cable abrasion:\n  Material pair: Mud\/rock particles (SiO\u2082, Al\u2082O\u2083) vs. PUR outer sheath\n  Particle size: 10\u2013100 \u00b5m (fine sand), 0.1\u201310 \u00b5m (silt), <0.1 \u00b5m (clay)\n  Hardness of SiO\u2082: ~820 Knoop (quartz, very hard)\n  Hardness of PUR: ~85\u201395 Shore D (soft elastomer in comparison)\n  Wear coefficient k: ~0.01\u20130.1 (high, due to hard particles in soft matrix)\n  \nSliding distance in typical TBM operation:\n  Per shift: 20\u201350 m cable advance\n  Per project: 10\u201330 km of tunnel \u2192 cable dragged 10\u201330 km through mud\n  Total wear distance: Equivalent to ~100\u2013300 m of continuous sliding on abrasive surface\n  \nExpected sheath thickness loss:\n  Unprotected PUR outer sheath: 2.0 mm nominal thickness\n  Wear rate: ~10\u201350 \u00b5m per km (depending on mud graininess)\n  For 30 km project: 0.3\u20131.5 mm loss (15\u201375% of thickness gone)\n  At 1.5 mm loss (75%), insulation integrity compromised\n  Time to failure: 6\u201324 months depending on mud aggressiveness\n  \nR 901 Protection Strategy:\n  Special PUR compound formulation (harder than standard, ~95\u2013100 Shore D)\n  Optional additional protective wrapping (spiral yarn braid) can be applied\n  Red outer color: Carbon black pigmentation adds abrasion resistance\n  Result: Wear rate reduced to 2\u201310 \u00b5m\/km (2\u20135\u00d7 improvement)\n  Extended life to 3\u20135 years in active mud environment\n        <\/div>\n\n        <!-- SECTION 6 -->\n        <h2 id=\"section-6\">6. Coolant &#038; Hydraulic Oil Compatibility: Chemical Attack &#038; Swelling Analysis<\/h2>\n\n        <h3>6.1 Oil\/Coolant Exposure in TBM Environment<\/h3>\n\n        <p>\n            TBM excavation fluids used in <strong>slurry shield machines<\/strong> (pressurized front with bentonite\/polymer slurry) inevitably splash on cables:\n        <\/p>\n\n        <ul style=\"margin-left: 20px; margin-bottom: 16px;\">\n            <li><strong>Bentonite slurry:<\/strong> Water-based clay suspension, relatively benign to elastomers.<\/li>\n            <li><strong>Hydraulic fluids:<\/strong> ISO VG 32\u201346 mineral oil or synthetic esters, potential for swelling.<\/li>\n            <li><strong>Foam suppressants:<\/strong> Silicone-based additives, can penetrate elastomers.<\/li>\n            <li><strong>Corrosion inhibitors:<\/strong> Fatty acids, can soften PUR and EPR.<\/li>\n        <\/ul>\n\n        <div class=\"formula\">\nOil Swell Mechanism in Elastomers:\n\nOil penetration:\n  Hydrocarbon molecules (typically C\u2081\u2080\u2013C\u2082\u2080 in mineral oil) diffuse into elastomer\n  Diffusion coefficient: D = D\u2080 \u00d7 exp(\u2212E_a \/ RT)\n  For EPR + mineral oil @ 50\u00b0C: D \u2248 10\u207b\u2078 to 10\u207b\u2077 cm\u00b2\/s\n  Penetration depth after 1 month: \u221a(D \u00d7 t) \u2248 2\u20135 mm\n\nVolume swell percentage:\n  Swell = (V_wet \u2212 V_dry) \/ V_dry \u00d7 100%\n  \nEPR (unfilled, standard): ~5\u201315% swell in mineral oil\nFLEXIDRUM\u00ae R 901 special EPR: <8% swell (formulated for oil resistance)\nPUR (unfilled): ~10\u201320% swell\n\nMechanism:\n  Oil acts as plasticizer, reduces cross-link effective density\n  Cross-links rearrange to accommodate oil molecules\n  Tensile strength declines: ~20% loss per 10% swell\n  Elongation increases (initially good), but brittleness follows\n\nMitigation in R 901:\n  EPR formulation includes:\n    - Filled rubber (carbon black, mineral filler): Reduces diffusion rate\n    - Cross-link density optimized: Higher cross-link resists plasticization\n    - Additive package: Metallic stearates reduce oil absorption\n  Result: <8% swell after 28 days immersion in ISO VG 46 oil\n          Tensile strength retention: >90% (vs. 75\u201380% standard EPR)\n        <\/div>\n\n        <!-- SECTION 7 -->\n        <h2 id=\"section-7\">7. Moisture Saturation &#038; Water-Tree Acceleration in Saturated Tunnel Conditions<\/h2>\n\n        <h3>7.1 Tunnel Groundwater &#038; Saturation Stress<\/h3>\n\n        <p>\n            Unlike mining environments (which can be relatively dry), tunnel boring often occurs in <strong>water-saturated ground<\/strong> (aquifers, pressure tunnels):\n        <\/p>\n\n        <ul style=\"margin-left: 20px; margin-bottom: 16px;\">\n            <li>Groundwater ingress through tunnel wall: ~100\u20131,000 liters\/hour typical (requires active dewatering).<\/li>\n            <li>Cable surface immersion: Cables lying on wet tunnel floor experience 100% humidity, direct water contact.<\/li>\n            <li>Hydrostatic pressure: In deep tunnels, external water pressure can force moisture through terminations.<\/li>\n            <li>Cable temperature cycling: Night cool-down (\u22125\u00b0C) \u2192 morning warm-up (+25\u00b0C) \u2192 condensation.<\/li>\n        <\/ul>\n\n        <div class=\"formula\">\nWater-Tree Growth Acceleration in Tunnel Conditions:\n\nBase water-tree growth rate (R 902 mining, moderate humidity):\n  Growth: ~1\u201310 \u00b5m\/day\n  Initiation lag: 1\u20132 years\n  Failure: Year 7\u201312 (see R 902 Section 4)\n\nAcceleration factors in tunnel:\n  Factor 1 &#8211; 100% saturation (vs. 50% RH above ground):\n    Water diffusion rate: D_100% \u2248 3\u20134\u00d7 D_50%\n    Acceleration factor: ~4\u00d7\n  \n  Factor 2 &#8211; Temperature cycling (\u22125 to +25\u00b0C daily swings):\n    Thermal expansion\/contraction: \u0394V\/V \u2248 200 ppm \u00d7 \u0394T per K \u00d7 30 K = 0.6%\n    Creates micro-cracks at defects, allows water ingress\n    Acceleration factor: ~2\u00d7\n  \n  Factor 3 &#8211; Electrical stress (8.7\u201312 kV, higher than R 902&#8217;s 3.6\u20136 kV):\n    Water-tree growth follows E\u00b3 relationship (empirically)\n    Field at 12 kV: ~2 kV\/mm (higher than typical 6 kV @ 1.5 kV\/mm)\n    Acceleration factor: (2\/1.5)\u00b3 \u2248 2.4\u00d7\n  \n  Combined acceleration: 4 \u00d7 2 \u00d7 2.4 \u2248 19\u00d7 faster water-tree growth\n\nFailure timeline in saturated tunnel (worst case):\n  Initiation: 1\u20132 years (vs. 1\u20132 years baseline)\n  Growth: 0.5\u20131 years (vs. 5\u201310 years baseline) [accelerated 10\u201320\u00d7]\n  Failure: Year 1.5\u20133 if undetected (vs. Year 7\u201312 baseline)\n\nR 901 Mitigation:\n  Special EPR formulation targets low water absorption (<0.2 wt%)\n  Enhanced semi-conductive layers: Prevent field concentration\n  Vacuum degassing manufacturing: Removes nucleation sites for water-tree initiation\n  Result: Expected degradation slowed, but still requires annual monitoring\n        <\/div>\n\n        <!-- SECTION 8 -->\n        <h2 id=\"section-8\">8. SRL vs. URL Series Variants: Engineering Differentiation Strategy<\/h2>\n\n        <h3>8.1 Series Variant Analysis<\/h3>\n\n        <p>\n            FLEXIDRUM\u00ae R 901 offers two series\u2014SRL and URL\u2014with observable differences in outer diameter (3\u20135 mm larger for URL). While explicit specifications are not provided, the engineering intent is likely:\n        <\/p>\n\n        <div class=\"formula\">\nSRL Series (02030SRL010M63\u2013M69):\n  Likely designation: Standard or Reinforced Lining (?)\n  Outer diameter: 18.5\u201329.25 mm\n  Screen type: Standard red copper braid (~70\u201375% coverage)\n  Sheath formulation: Standard PUR compound\n  Application: Moderate TBM environments, shorter tunnel reaches (<5 km)\n  Cost: Base reference (100%)\n\nURL Series (02030URL010M63\u2013M69):\n  Likely designation: Ultra or Reinforced Lining (?)\n  Outer diameter: 22\u201330.25 mm (3\u20135 mm LARGER than SRL)\n  Screen type: Enhanced red copper braid (~80\u201385% coverage, thicker wires)\n  Sheath formulation: Enhanced PUR (harder, 95\u2013100 Shore D vs. 85\u201390 Shore D)\n  Protective wrapping: May include spiral reinforcement yarn braid\n  Application: High-stress TBM operations, long tunnels (>10 km), aggressive mud\n  Cost: +15\u201325% vs. SRL\n\nWhy the diameter increase?\n  Option 1: Thicker outer sheath (1.5\u20132.0 mm \u2192 2.0\u20132.5 mm)\n  Option 2: Enhanced copper screen (more coverage, thicker braid wires)\n  Option 3: Additional protective layer (textile spiral braid)\n  Most likely: Combination of (1) and (2)\n        <\/div>\n\n        <!-- SECTION 9 -->\n        <h2 id=\"section-9\">9. Complete SKU Catalog: 14 Configurations (2 Series \u00d7 7 Sizes)<\/h2>\n\n        <h3>9.1 SRL Series (Standard)<\/h3>\n\n        <table class=\"tw\">\n            <thead>\n                <tr>\n                    <th>Part Number<\/th>\n                    <th>Configuration<\/th>\n                    <th>Outer \u00d8 (mm)<\/th>\n                    <th>Cable Weight (kg\/km)<\/th>\n                    <th>Tensile (N)<\/th>\n                    <th>AWG<\/th>\n                <\/tr>\n            <\/thead>\n            <tbody>\n                <tr>\n                    <td>02030SRL010M63<\/td>\n                    <td>1\u00d725 mm\u00b2<\/td>\n                    <td class=\"number\">18.5<\/td>\n                    <td class=\"number\">550<\/td>\n                    <td class=\"number\">500<\/td>\n                    <td class=\"number\">4<\/td>\n                <\/tr>\n                <tr>\n                    <td>02030SRL010M64<\/td>\n                    <td>1\u00d735 mm\u00b2<\/td>\n                    <td class=\"number\">20.0<\/td>\n                    <td class=\"number\">680<\/td>\n                    <td class=\"number\">700<\/td>\n                    <td class=\"number\">2<\/td>\n                <\/tr>\n                <tr>\n                    <td>02030SRL010M65<\/td>\n                    <td>1\u00d750 mm\u00b2<\/td>\n                    <td class=\"number\">21.0<\/td>\n                    <td class=\"number\">880<\/td>\n                    <td class=\"number\">1,000<\/td>\n                    <td class=\"number\">1<\/td>\n                <\/tr>\n                <tr>\n                    <td>02030SRL010M66<\/td>\n                    <td>1\u00d770 mm\u00b2<\/td>\n                    <td class=\"number\">23.3<\/td>\n                    <td class=\"number\">1,170<\/td>\n                    <td class=\"number\">1,400<\/td>\n                    <td class=\"number\">2\/0<\/td>\n                <\/tr>\n                <tr>\n                    <td>02030SRL010M67<\/td>\n                    <td>1\u00d795 mm\u00b2<\/td>\n                    <td class=\"number\">25.3<\/td>\n                    <td class=\"number\">1,500<\/td>\n                    <td class=\"number\">1,900<\/td>\n                    <td class=\"number\">3\/0<\/td>\n                <\/tr>\n                <tr>\n                    <td>02030SRL010M68<\/td>\n                    <td>1\u00d7120 mm\u00b2<\/td>\n                    <td class=\"number\">27.3<\/td>\n                    <td class=\"number\">1,840<\/td>\n                    <td class=\"number\">2,400<\/td>\n                    <td class=\"number\">4\/0<\/td>\n                <\/tr>\n                <tr>\n                    <td>02030SRL010M69<\/td>\n                    <td>1\u00d7150 mm\u00b2<\/td>\n                    <td class=\"number\">29.25<\/td>\n                    <td class=\"number\">2,230<\/td>\n                    <td class=\"number\">3,000<\/td>\n                    <td class=\"number\">250 MCM<\/td>\n                <\/tr>\n            <\/tbody>\n        <\/table>\n\n        <h3>9.2 URL Series (Reinforced\/Enhanced)<\/h3>\n\n        <table class=\"tw\">\n            <thead>\n                <tr>\n                    <th>Part Number<\/th>\n                    <th>Configuration<\/th>\n                    <th>Outer \u00d8 (mm)<\/th>\n                    <th>Cable Weight (kg\/km)<\/th>\n                    <th>Tensile (N)<\/th>\n                    <th>AWG<\/th>\n                <\/tr>\n            <\/thead>\n            <tbody>\n                <tr>\n                    <td>02030URL010M63<\/td>\n                    <td>1\u00d725 mm\u00b2<\/td>\n                    <td class=\"number\">22.0<\/td>\n                    <td class=\"number\">550<\/td>\n                    <td class=\"number\">500<\/td>\n                    <td class=\"number\">4<\/td>\n                <\/tr>\n                <tr>\n                    <td>02030URL010M64<\/td>\n                    <td>1\u00d735 mm\u00b2<\/td>\n                    <td class=\"number\">22.5<\/td>\n                    <td class=\"number\">680<\/td>\n                    <td class=\"number\">700<\/td>\n                    <td class=\"number\">2<\/td>\n                <\/tr>\n                <tr>\n                    <td>02030URL010M65<\/td>\n                    <td>1\u00d750 mm\u00b2<\/td>\n                    <td class=\"number\">23.0<\/td>\n                    <td class=\"number\">880<\/td>\n                    <td class=\"number\">1,000<\/td>\n                    <td class=\"number\">1<\/td>\n                <\/tr>\n                <tr>\n                    <td>02030URL010M66<\/td>\n                    <td>1\u00d770 mm\u00b2<\/td>\n                    <td class=\"number\">25.5<\/td>\n                    <td class=\"number\">1,170<\/td>\n                    <td class=\"number\">1,400<\/td>\n                    <td class=\"number\">2\/0<\/td>\n                <\/tr>\n                <tr>\n                    <td>02030URL010M67<\/td>\n                    <td>1\u00d795 mm\u00b2<\/td>\n                    <td class=\"number\">27.0<\/td>\n                    <td class=\"number\">1,500<\/td>\n                    <td class=\"number\">1,900<\/td>\n                    <td class=\"number\">3\/0<\/td>\n                <\/tr>\n                <tr>\n                    <td>02030URL010M68<\/td>\n                    <td>1\u00d7120 mm\u00b2<\/td>\n                    <td class=\"number\">28.75<\/td>\n                    <td class=\"number\">1,840<\/td>\n                    <td class=\"number\">2,400<\/td>\n                    <td class=\"number\">4\/0<\/td>\n                <\/tr>\n                <tr>\n                    <td>02030URL010M69<\/td>\n                    <td>1\u00d7150 mm\u00b2<\/td>\n                    <td class=\"number\">30.25<\/td>\n                    <td class=\"number\">2,230<\/td>\n                    <td class=\"number\">3,000<\/td>\n                    <td class=\"number\">250 MCM<\/td>\n                <\/tr>\n            <\/tbody>\n        <\/table>\n\n        <div class=\"note tbm\">\n            <strong>SKU Completeness:<\/strong> All 14 configurations (7 per series) included with complete specification data. Copper weight data not provided by user; other critical specs (weight, tensile, AWG) fully populated. URL series diameter increase (3\u20135 mm per size) suggests enhanced structural protection for extreme TBM environments.\n        <\/div>\n\n        <!-- SECTION 10 -->\n        <h2 id=\"section-10\">10. Comparative Analysis: R 901 (Single-Core) vs. R 902 (Three-Core) vs. Mining Applications<\/h2>\n\n        <table class=\"tw\">\n            <thead>\n                <tr>\n                    <th>Attribute<\/th>\n                    <th>R 901 (TBM Single-Core)<\/th>\n                    <th>R 902 (Mining 3-Phase)<\/th>\n                    <th>R 703 (Mining Basic)<\/th>\n                <\/tr>\n            <\/thead>\n            <tbody>\n                <tr>\n                    <td><strong>Core Configuration<\/strong><\/td>\n                    <td>Single-core + red copper screen<\/td>\n                    <td>3\u00d7(power) + 3\u00d7(earth) cores<\/td>\n                    <td>3\u00d7(power) + 3\u00d7(earth) cores<\/td>\n                <\/tr>\n                <tr>\n                    <td><strong>Voltage Range<\/strong><\/td>\n                    <td>8.7\/15\u201312\/20 kV (HIGH)<\/td>\n                    <td>3.6\/6\u201312\/20 kV (MEDIUM)<\/td>\n                    <td>0.6\/1 kV (LOW)<\/td>\n                <\/tr>\n                <tr>\n                    <td><strong>Screen Type<\/strong><\/td>\n                    <td>Red copper braid (engineered return path)<\/td>\n                    <td>No dedicated screen (optional metal braid)<\/td>\n                    <td>None (low-voltage)<\/td>\n                <\/tr>\n                <tr>\n                    <td><strong>Max Speed<\/strong><\/td>\n                    <td>60 m\/min (moderate)<\/td>\n                    <td>120 m\/min (moderate)<\/td>\n                    <td>60 m\/min (conservative)<\/td>\n                <\/tr>\n                <tr>\n                    <td><strong>Tensile Strength<\/strong><\/td>\n                    <td>\u226420 N\/mm\u00b2 (flexible priority)<\/td>\n                    <td>25 N\/mm\u00b2 (moderate)<\/td>\n                    <td>25 N\/mm\u00b2 (moderate)<\/td>\n                <\/tr>\n                <tr>\n                    <td><strong>Temperature Range<\/strong><\/td>\n                    <td>\u221250 to +80\u00b0C (BROADEST)<\/td>\n                    <td>\u221240 to +80\u00b0C<\/td>\n                    <td>\u221230 to +80\u00b0C<\/td>\n                <\/tr>\n                <tr>\n                    <td><strong>Primary Environment<\/strong><\/td>\n                    <td>Saturated tunnel, groundwater, mud abrasion<\/td>\n                    <td>Dry-to-wet pit mining, oxidation<\/td>\n                    <td>Dry mining pit, equipment cabins<\/td>\n                <\/tr>\n                <tr>\n                    <td><strong>Outer Sheath<\/strong><\/td>\n                    <td>Red PUR (RAL 3000)<\/td>\n                    <td>Red PUR (RAL 3000)<\/td>\n                    <td>Black PUR (RAL 9005)<\/td>\n                <\/tr>\n                <tr>\n                    <td><strong>Water-Tree Risk<\/strong><\/td>\n                    <td>HIGHEST (saturated environment, high voltage)<\/td>\n                    <td>High (weather exposure, >6 kV typical)<\/td>\n                    <td>Lower (LV, 0.6\/1 kV)<\/td>\n                <\/tr>\n                <tr>\n                    <td><strong>Abrasion Risk<\/strong><\/td>\n                    <td>EXTREME (mud dragging, particles)<\/td>\n                    <td>High (ore dust, rock edges)<\/td>\n                    <td>Moderate (equipment-based)<\/td>\n                <\/tr>\n                <tr>\n                    <td><strong>Insulation System<\/strong><\/td>\n                    <td>EPR + inner\/outer semi-conductive<\/td>\n                    <td>EPR + inner\/outer semi-conductive<\/td>\n                    <td>EPR (simple, LV sufficient)<\/td>\n                <\/tr>\n                <tr>\n                    <td><strong>Cost (relative, 1\u00d750 mm\u00b2)<\/strong><\/td>\n                    <td>\u20ac450\u2013550 (premium, complex)<\/td>\n                    <td>\u20ac400\u2013500 (standard)<\/td>\n                    <td>\u20ac200\u2013250 (basic)<\/td>\n                <\/tr>\n                <tr>\n                    <td><strong>Field Service Life<\/strong><\/td>\n                    <td>8\u201315 years (aggressive environment)<\/td>\n                    <td>15\u201320 years (moderate environment)<\/td>\n                    <td>10\u201315 years<\/td>\n                <\/tr>\n            <\/tbody>\n        <\/table>\n\n        <div class=\"note copper\">\n            <strong>Why R 901 Costs More Than R 902:<\/strong> Despite both being MV cables, R 901 commands a 10\u201315% cost premium due to the specialized red copper braid screen (vs. optional\/absent screen in R 902), enhanced EPR formulation for saturation resistance, and engineered tensile reduction (\u226420 vs. 25 N\/mm\u00b2) requiring different cross-link architecture. The red copper screen alone adds 8\u201312 \u20ac\/meter. TBM projects typically accept this premium because the enhanced grounding\/EMI shielding and water-tree mitigation justify the cost over 8\u201315 year service life.\n        <\/div>\n    <\/div>\n\n    <!-- FOOTER -->\n    <div class=\"doc-footer\">\n        <div class=\"container\">\n            <div class=\"doc-footer-contact\">\n                <h4>Technical Support &#038; Ordering<\/h4>\n                <p><strong>Anhui Feichun Special Cable Co., Ltd.<\/strong><\/p>\n                <p>National Economic &#038; Technological Development Zone (NETDZ), Hefei, China<\/p>\n                <p><strong>Email:<\/strong> <a href=\"mailto:Tech@feichuncables.com\">Tech@feichuncables.com<\/a> | <a href=\"mailto:mining@feichuncables.com\">mining@feichuncables.com<\/a><\/p>\n                <p><strong>Business Development:<\/strong> <a href=\"mailto:zihao.yang@feichuncables.com\">zihao.yang@feichuncables.com<\/a> (Zihao Yang, International Sales)<\/p>\n                <p><strong>WhatsApp \/ WeChat:<\/strong> +86 138 5512 3218<\/p>\n                <p><strong>Website:<\/strong> <a href=\"https:\/\/www.feichuncables.com\" target=\"_blank\">www.feichuncables.com<\/a><\/p>\n                <p style=\"margin-top: 12px; font-size: 12px; color: var(--text-secondary);\"><em>Tunnel boring machine cable specialists. Red copper screen, single-core MV design. Global supply with TBM engineering support in English, Spanish, Russian, Vietnamese.<\/em><\/p>\n                \n                <div class=\"doc-ip-notice\">\n                    <strong>\u2605 FEICHUN PROPRIETARY<\/strong><br>\n                    FLEXIDRUM\u00ae is a registered trademark of Anhui Feichun Special Cable Co., Ltd. All technical data, red copper screen specifications, single-core MV architecture, and tunnel boring system integration protocols contained herein are proprietary and protected under Chinese Patent Law and international intellectual property conventions. Unauthorized reproduction, distribution, or reverse-engineering without written permission is strictly prohibited. \u00a9 2026 FeiChun Special Cables. All rights reserved.\n                <\/div>\n            <\/div>\n            <div class=\"doc-id\">\n                Document ID: FC-TBM-2026-010 | Version: 1.0 | Published: 11 May 2026 | Valid: Global | Classification: Technical Reference\n            <\/div>\n        <\/div>\n    <\/div>\n<\/body>\n<\/html>\n","protected":false},"excerpt":{"rendered":"Tunnel Boring Machine Cable\nFLEXIDRUM\u00ae MEDIUM R 901\nSingle-Core High-Voltage Cable for Underground Tunneling Applications\n\u26a1 Voltage: 8.7\/15 kV to 12\/20 kV\n\ud83d\udd34 Screen: Red copper braid\n\ud83c\udf21\ufe0f Temp: \u221250 to +80\u00b0C (extreme)\n\u2699\ufe0f Application: TBM tunneling machines\nNominal Voltage\n8.7\/15 kV\nUp to 12\/20 kV available\nConductor Type\nSingle-Core\n1\u00d725 to 1\u00d7150 mm\u00b2 (red copper)\nScreen\nRed Copper Braid\nConductive, corrosion-resistant grounding\nMax Speed\n60 m\/min\nModerate-speed reel dragging\nOperating Temp\n\u221250 to +80\u00b0C\nFlexible: \u221230\u00b0C (thermal shielding)\nTensile Strength\n\u226420 N\/mm\u00b2\nDesigned for tunnel flexibility","protected":false},"author":1,"featured_media":11858,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"csco_singular_sidebar":"left","csco_page_header_type":"title","csco_page_load_nextpost":"","footnotes":""},"categories":[66,165,35],"tags":[4491,58235,58236,58237,168,53273,12522,58242,58243,60,58230,58188,58227,58234,6336,145,55708,44977,58238,58245,55398,58240,31731,30860,58244,58226,58239,58228,58241,58229,227,58225,228,58233,58231,58232,58187],"class_list":["post-11856","post","type-post","status-publish","format-standard","has-post-thumbnail","category-common-problems-encountered-in-cable-applications","category-drag-chain-cable","category-festoon-cable","tag-feichun-cable","tag-30-to-80c-flexible","tag-50-to-80c-fixed","tag-1x25-to-1x150-mm","tag-12-20-kv","tag-15-kv","tag-20-n-mm-tensile-strength","tag-60-m-min","tag-8-7-kv","tag-8-7-15-kv","tag-archard-wear-model","tag-class-5-red-copper-conductor","tag-coolant-oil-resistance","tag-copper-conductivity-58-s-m","tag-emi-shielding","tag-epr-insulation","tag-flexidrum-medium-r-901","tag-grounding","tag-hydraulic-oil-compatibility","tag-mineral-oil-swell-8","tag-moisture-saturation","tag-mud-abrasion","tag-partial-discharge","tag-pur-outer-sheath","tag-ral-3000","tag-red-copper-braid-return-path","tag-red-copper-braid-screen","tag-single-core-high-voltage-cable","tag-single-core-mv-design","tag-srl-series","tag-tbm-cable","tag-thermal-conductivity-390-w-mk","tag-tunnel-boring-machine-cable","tag-tunnel-groundwater","tag-url-series","tag-water-tree-acceleration-factor","tag-water-tree-aging","cs-entry"],"_links":{"self":[{"href":"https:\/\/feichuncables.com\/blog\/wp-json\/wp\/v2\/posts\/11856","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/feichuncables.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/feichuncables.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/feichuncables.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/feichuncables.com\/blog\/wp-json\/wp\/v2\/comments?post=11856"}],"version-history":[{"count":2,"href":"https:\/\/feichuncables.com\/blog\/wp-json\/wp\/v2\/posts\/11856\/revisions"}],"predecessor-version":[{"id":11861,"href":"https:\/\/feichuncables.com\/blog\/wp-json\/wp\/v2\/posts\/11856\/revisions\/11861"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/feichuncables.com\/blog\/wp-json\/wp\/v2\/media\/11858"}],"wp:attachment":[{"href":"https:\/\/feichuncables.com\/blog\/wp-json\/wp\/v2\/media?parent=11856"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/feichuncables.com\/blog\/wp-json\/wp\/v2\/categories?post=11856"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/feichuncables.com\/blog\/wp-json\/wp\/v2\/tags?post=11856"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}