9x2.5MKVVRP-450/750V Flame-retardant Mining Control Cable Technical Analysis
I. Model Definition and Structure


Model breakdown


9x2.5: 9-core conductor, each strand with a cross-sectional area of 2.5mm², suitable for multi-loop control signal transmission.
MKVVRP‌：
Coal Mine Cable (compliant with underground safety regulations)
Control Cable
VV: Polyvinyl Chloride (PVC) Insulation and Sheath
R: Soft conductor (Class 5 stranded copper wire)
P: Copper wire braided shielding layer (coverage ≥ 85%).


Structure


Conductor: Oxygen-free copper stranded soft conductor (multiple fine copper wires), conductivity ≥99.9%, excellent flexibility.
Insulation: Made of PVC material, temperature resistance -20℃ to 70℃, insulation resistance ≥60MΩ·km (at 20℃).
Screening Layer: Tin-plated copper wire braid, electromagnetic interference (EMI) resistance ≥60dB.
Sheath: Flame-retardant PVC (oxygen index ≥ 28), thickness ≥ 1.2mm, oil and acid/alkali resistant.
Section II: Key Performance Parameters
Electrical Performance: Rated voltage 450/750V, withstand voltage ≥2000V/1 minute without breakdown under industrial frequency; conductor DC resistance ≤7.41Ω/km (20℃).
Flame Retardant Rating: Meets MT 818-2009 standard, passed A-type bundle combustion test, self-extinguishing time ≤ 30 seconds.
Mechanical Properties: Dynamic bending radius ≥ 12 times the outer diameter, tensile strength ≥ 1500N.
Section 3: Application Scenarios and Advantages


Typical Applications


Underground coal mine automation system: Connects PLCs, sensors, and signals (such as gas monitoring, ventilation control).
Mobile Device Power Supply: Control circuits for frequently moving equipment such as coal mining machines and conveyors.


Safety Advantages


Flame-retardant PVC sheath prevents fire spread; its low-smoke characteristic reduces secondary fire hazards.
The shielding layer effectively suppresses strong electromagnetic interference underground, ensuring signal stability.
IV. Installation and Maintenance Standards
Laying Requirements: Ambient temperature ≥ -10°C, avoid parallel spacing with power cables less than 300mm; armor cable bending radius ≥ 12 times the outer diameter.
Grounding Standard: Single-point grounding for shielding layer (ground resistance ≤ 4Ω)
Inspection and Maintenance: Test insulation resistance every six months (normal condition ≥10MΩ/km), inspect sheath wear and shielding integrity.