Mica Tape Lapped Mineral Insulated Corrugated Copper Sheath Cable (RTTZ Series)

Executive Standards
This product is designed and manufactured in strict accordance with Chinese national standards and relevant industry technical requirements:
- GB/T 34926-2017: "Corrugated copper sheath cables with mica tape mineral insulation and terminations for rated voltages up to and including 0.6/1 kV" (core execution standard).
- GB/T 19666-2019: General requirements for flame retardant and fire-resistant characteristics.
- It also meets the highest international requirements of BS 6387 for fire resistance, water spray, and mechanical shock tests.

Model Code Definitions
- R: Flexible code.
- T: Copper conductor.
- T: Corrugated copper sheath.
- Z: Mineral insulating material (mica tape lapping).
- WD: Halogen-free low smoke (optional outer sheath characteristic).
- Y / V: Outer sheath material (Y – polyolefin; V – PVC).
- RTTZ: Copper core, mica tape mineral insulated, corrugated copper sheathed cable.
- WD-RTTYZ: Copper core, mica tape mineral insulated, corrugated copper sheathed, low-smoke zero-halogen polyolefin sheathed cable.

Product Specification Range
The cable offers a comprehensive range of specifications from single-core to multi-core, covering various power and control circuits:
- 1 core: 10 – 400 mm²
- 2 cores: 1.5 – 150 mm²
- 3 cores: 1.5 – 150 mm²
- 4 cores: 1.5 – 120 mm²
- 5 cores: 1.5 – 95 mm²
- Combination configurations:
  - (3×2.5+1×1.5) to (3×120+1×70) mm²
  - (3×2.5+2×1.5) to (3×95+2×50) mm²
  - (4×2.5+1×1.5) to (4×95+1×50) mm²

Core Technical Parameters
1. Rated voltage (U₀/U): 0.6/1 kV.
2. Operating temperature: The maximum continuous permissible conductor operating temperature is 90 °C. Under extreme fire conditions, due to the very high melting points of the mica tape and copper sheath, the cable can withstand higher instantaneous temperatures.
3. Fire resistance performance: Meets the requirements of GB/T 19216 and BS 6387 Category CWZ (withstanding combustion, water spray, and mechanical shock tests under a 950 °C flame while maintaining uninterrupted power supply).
4. Bending radius: The minimum bending radius is typically 10D – 15D (D is the overall cable diameter), which is much better than that of rigid mineral cables.
5. Electrical tests: The finished cable must withstand a power-frequency AC voltage withstand test. The insulation resistance must meet standard requirements both at high temperature and after cooling.

Cable Structural Characteristics
- High-flexibility conductor: Uses high-quality annealed copper conductor with a stranded construction to ensure good bendability.
- Dual fire-resistant layers: Multi-layer synthetic mica tape is lapped, and mineral insulating material is filled between cores to form a reliable fire-resistant barrier.
- Corrugated copper sheath: A copper tube sheath formed by a continuous welding and corrugation process on the outer layer, providing very strong sealing properties (waterproof and moisture-proof), mechanical protection strength, and good heat dissipation.
- Optional outer sheath: Depending on the installation environment, a PVC or low-smoke zero-halogen sheath can be added for corrosion protection and appearance.

Applicable Scenarios
- High-rise and super high-rise buildings: Power distribution circuits for critical loads such as fire-fighting lifts, emergency lighting, and smoke exhaust fans.
- Major transportation hubs: Subway stations, high-speed rail stations, airport terminals, and inside tunnels.
- Densely populated places: Hospitals, schools, theatres, sports venues, and large shopping centers.
- Special industrial fields: Petrochemical, metallurgical, substations, and nuclear power plants (non-containment areas) and other sites with stringent fire and water resistance requirements.

Product Advantages and Installation Recommendations
- Long joint-free lengths: The RTTZ series can be produced continuously over long distances, reducing intermediate joints and greatly lowering the risk of electrical faults.
- Easy installation: The flexible construction allows it to be installed in cable trays or conduits like ordinary power cables, without the need for expensive specialized bending tools.
- Environmental safety: If the WD-RTTYZ type is selected, the outer sheath is halogen-free, non-toxic in fire, and produces very low smoke, effectively protecting life safety.
- Installation reminder: During installation, dedicated mineral cable terminations and sealing accessories should be used, and the continuous grounding of the corrugated copper sheath should be ensured to guarantee the electrical stability of the entire system.