BTTZ 0.6/1kV Rigid Mineral-Insulated Copper-Sheathed Cable
BTTZ is the original mineral-insulated cable construction: solid copper conductors embedded in compressed magnesium oxide powder inside a seamless copper sheath. The all-inorganic construction has no flammable components, no smoke under fire, and effectively unlimited fire survival — limited only by the eventual melting of the copper sheath at 1083°C.
Technical Specifications
| Conductor | Solid annealed copper |
| Insulation | Compressed magnesium oxide (MgO) |
| Outer sheath | Seamless copper, drawn |
| Fire-resistance ceiling | Copper melting point 1083°C |
| Smoke under fire | Zero (all-inorganic) |
| Halogen content | Zero |
| Rated voltage | 0.6/1 kV |
| Cross-sections available | 1 – 25 mm² |
| Cores available | 1 / 2 / 3 / 4 / 7 |
| Termination | Specialized end-seal kit required |
| Design life | > 50 years (no organic degradation) |
Compliance Standards
- ✓GB/T 13033
- ✓IEC 60702-1
- ✓BS 6207
Overview
Solid copper conductors, magnesium oxide (MgO) mineral powder insulation compressed to >2.5 g/cm³, seamless copper outer sheath drawn down over the assembly. No organic components anywhere in the cable — under fire, the cable continues to function until the copper sheath itself melts at 1083°C. Significantly more demanding to terminate than flexible YTTW (requires specialized end-sealing kits) but the most certain fire-resistant performance available.
Key Features
All-inorganic construction
No organic components anywhere — fire resistance is limited only by copper-sheath melting at 1083°C.
Zero smoke under fire
Mineral insulation produces no combustion products — usable in occupied spaces where any smoke is unacceptable.
50-year design life
No organic insulation to age — the only degradation mode is moisture ingress at terminations, controlled by proper end-seal procedure.
Applications
Tunnel emergency power
Road, rail, and metro tunnel emergency lighting and ventilation power where the most rigorous fire survival is mandated.