1. Technical Section

Product Name: “Noan‑G20F” Underground Telephone Cable
Application: Underground telephone lines with twenty simultaneous pairs, suitable for underground routes, ducts, and indoor environments requiring protection against noise and environmental conditions.

Internal Structure

Conductor: CCAM (Copper‑Clad Aluminum) with 60/0 structure (60 very fine strands)
Effective conductor area: Designed per project requirements (e.g., ~0.13 mm² or ~0.17 mm²)
Pair structure: Twenty twisted pairs
Shield: Laminated aluminum foil longitudinally wrapped around the core (100% coverage)
Drain Wire: Auxiliary conductor (copper or tinned copper) for connecting the shield to ground
Insulation per conductor: PVC or PE suitable for underground use
Outer Jacket: UV-resistant PVC or a combination for outdoor installation

Electrical and Performance Specifications

Conductor diameter: Based on reference “20-pair” cable examples, approximately 0.60 mm per conductor
Conductor resistance at 20 °C (max): ≤ 186 Ω/km for ~0.60 mm conductor (per 20-pair reference)
Insulation resistance (min): ≥ 5000 MΩ·km
Test voltage: AC 1500 V (1 min) / DC 2250 V (1 min) without breakdown
Operating temperature: ‑20 °C to +60 °C
Capacitance and impedance: Twisted pair design reduces crosstalk and pair-to-pair interference
Minimum bending radius: 10× overall cable diameter (or per manufacturer instructions)

Installation and Maintenance Notes

Install in ducts, underground, or protected routes
Protect passages through obstacles with clips or protective sleeves
Connect shield to ground at a single point for optimal performance
Observe bending radius and avoid sharp bends
Perform insulation resistance and line performance tests after installation

2. Content Section

Noan‑G20F Twenty-Pair Shielded Underground Telephone Cable

Noavaran Niroye Paytakht is proud to offer the “Noan‑G20F” cable; this twenty-pair underground telephone cable with full foil shielding is designed for indoor and underground environments needing simultaneous transmission of multiple telephone lines. The lightweight CCAM conductor with 60/0 strand structure, combined with proper insulation and aluminum shielding, provides high performance against environmental interference. The “Noan‑G20F” cable is ideal for urban or intercity projects requiring multiple telephone lines in a single underground route, offering environmental durability, stable signals, and reliable performance.

Key Features

Twenty twisted pairs
Full foil shield around the core
Lightweight CCAM conductor with 60/0 strand structure
Robust design for indoor and underground installation
High insulation resistance
Optimal performance under environmental conditions

3. Description, Applications, and Comparative Analysis

Suitable Applications

Underground telephone lines with a high number of pairs
Underground or in-structure routes in telecom projects
Areas with high electromagnetic interference potential
Urban or rural areas requiring multiple lines in a single route

Advantages

Simultaneous transmission of multiple lines without separate cables
Effective noise protection due to foil shield
Reduced installation cost using a single cable for multiple pairs
Lighter weight and lower cost compared to all-copper cables

Disadvantages

Higher conductor resistance compared to all-copper cables
Shield performance decreases if not properly grounded
Precise installation and adherence to standards are essential
Signal loss may be noticeable over long distances

Comparison with Lower-Pair Models

Compared to 1- or 2-pair cables, twenty-pair cables have higher core density, which may increase crosstalk; precise pair twist length and continuous foil design are essential
Production cost is higher, but the advantage of multiple lines in a single cable is significant

Quality Assurance and Production Control

Precise control of strand count (60 strands) and conductor uniformity
Ensured foil thickness, adhesion, and quality
Insulation, thermal aging, mechanical, and vibration testing on samples
Product name, company name, technical specifications, and production date printed on the cable
Provision of insulation resistance and performance test reports to customers