Anhui Tongdu International Trade Co., Ltd.
| Conductor (×1, earth) | Copper, Class 2 stranded flexible, nominal 7×∅2.14 mm (25 mm²), conductor Ø ≈ 6.4–7.2 mm |
| Approx. weight | 3.8 – 4.6 kg/m (3800–4600 kg/km) |
| Packaging Details | General Packaging or As Requirements |
| Inner sheath | Copper tape/foil (continuous, gas-tight), thickness ≈ 0.3–0.5 mm |
| Conductor material | Copper (Cu) |
| Design outer diameter | ≈ 33 mm |
| Outer sheath thickness | 1.5 mm |
| Conductor class | Class 2 stranded flexible |
| Supply Ability | 100000 meters per month |
| Conductor nominal area | 50 mm² (phase/neutral, ×4), 25 mm² (earth, ×1) |
| Insulation thickness | 1.5 mm |
| Overall cable diameter | 30 – 36 mm |
| Insulation | Mineral (ceramic compound / magnesium oxide based), inorganic, non-combustible, nominal thickness 1.5 mm (typical) |
| Conductor (×4, phase/neutral) | Copper, Class 2 stranded flexible, nominal 19×∅1.83 mm (50 mm²), conductor Ø ≈ 9.2–10.5 mm |
| Design weight | ≈ 4150 kg/km |
| Separator | Mica tape or ceramic paper wrap between cores |
| Payment Terms | L/C,T/T |
| Outer sheath | LSZH (low-smoke zero-halogen) compound, nominal thickness 1.5 mm (typical), colour: orange or red |
| Copper inner sheath thickness | 0.3–0.5 mm |
| Delivery Time | Less than 15 days |
| Number of cores | 5 |
| Conductor construction | 19×1.83 mm (50 mm²), 7×2.14 mm (25 mm²) |
| Model Number | BTTRZ x50mm²+1x25mm² |
| Certification | CE/ISO/CCC |
| Brand Name | TONGDU |
| Place of Origin | China |
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Product Specification
| Conductor (×1, earth) | Copper, Class 2 stranded flexible, nominal 7×∅2.14 mm (25 mm²), conductor Ø ≈ 6.4–7.2 mm | Approx. weight | 3.8 – 4.6 kg/m (3800–4600 kg/km) |
| Packaging Details | General Packaging or As Requirements | Inner sheath | Copper tape/foil (continuous, gas-tight), thickness ≈ 0.3–0.5 mm |
| Conductor material | Copper (Cu) | Design outer diameter | ≈ 33 mm |
| Outer sheath thickness | 1.5 mm | Conductor class | Class 2 stranded flexible |
| Supply Ability | 100000 meters per month | Conductor nominal area | 50 mm² (phase/neutral, ×4), 25 mm² (earth, ×1) |
| Insulation thickness | 1.5 mm | Overall cable diameter | 30 – 36 mm |
| Insulation | Mineral (ceramic compound / magnesium oxide based), inorganic, non-combustible, nominal thickness 1.5 mm (typical) | Conductor (×4, phase/neutral) | Copper, Class 2 stranded flexible, nominal 19×∅1.83 mm (50 mm²), conductor Ø ≈ 9.2–10.5 mm |
| Design weight | ≈ 4150 kg/km | Separator | Mica tape or ceramic paper wrap between cores |
| Payment Terms | L/C,T/T | Outer sheath | LSZH (low-smoke zero-halogen) compound, nominal thickness 1.5 mm (typical), colour: orange or red |
| Copper inner sheath thickness | 0.3–0.5 mm | Delivery Time | Less than 15 days |
| Number of cores | 5 | Conductor construction | 19×1.83 mm (50 mm²), 7×2.14 mm (25 mm²) |
| Model Number | BTTRZ x50mm²+1x25mm² | Certification | CE/ISO/CCC |
| Brand Name | TONGDU | Place of Origin | China |
| High Light | 1x25mm2 fire resistant cable ，fire resistant cable mineral ，emergency power copper sheathed cable | ||
BTTRZ x50mm²+1x25mm² Mineral Insulated Fire Resistant Copper Sheathed Cable for Emergency Power
|
Code |
Meaning |
|---|---|
|
B |
Fixed wiring cable (Class B — building wire/power cable) |
|
T |
Copper conductor (Tong = copper) |
|
T |
Copper sheath (Tong = copper) |
|
R |
Flexible (Rou = flexible) |
|
Z |
Heavy duty (Zhong = heavy) |
|
4×50 mm² + 1×25 mm² |
Four 50 mm² phase cores + one 25 mm² earth core (5-core: 3P+1N+1PE) |
Construction: Copper conductors, mineral insulation (magnesium oxide or ceramic compound), copper sheath, flexible design with overall LSZH outer sheath.
1. Overview & Ratings. BTTRZ 4×50+1×25 — flexible mineral-insulated (MgO) copper-sheathed fire-resistant cable, four 50 mm² copper power cores (L1/L2/L3/N) plus one 25 mm² PE core, embedded in compacted magnesium oxide powder inside a continuous corrugated copper tube, rated 0.6/1 kV; built and tested per GB/T 13033 / BS 6387. The cable maintains circuit integrity at 950 °C for 180 minutes. Ø ≈ 38.5 mm, ≈ 3850 kg/km, wooden drums.
2. Construction Stack (Conductor → Outer).
| Layer | Build | Wall | Diameter |
|---|---|---|---|
| Conductors (×5) | Cu: 4×50 mm² (L1/L2/L3/N) + 1×25 mm² (PE) | — | ≈ 9.5 / 6.3 mm |
| MgO insulation | Magnesium oxide powder, compacted | ≈ 1.5 around each | — |
| Corrugated Cu tube | Continuous welded copper | ≈ 0.9 mm | ≈ 36.5 mm |
| Outer PVC sheath | PVC, black/red (corrosion protection) | ≈ 1.0 mm | ≈ 38.5 mm (finished) |
3. Electrical Characteristics. R ≤ 0.387 Ω/km (50 mm²) / ≤ 0.741 Ω/km (25 mm²) at 20 °C; routine test 3.5 kV AC / 5 min; insulation resistance ≥ 1000 MΩ·km (MgO — extremely high). Reference ampacity ≈ 175 A (4×50 loaded, free air, 30 °C).
|
Property |
Value |
|---|---|
|
Insulation material |
Mineral ceramic compound (inorganic, non-combustible) |
|
Outer sheath material |
LSZH (low-smoke zero-halogen) |
|
Long-term service temp. |
90 °C (continuous, limited by termination) |
|
Short-circuit temp. (≤5 s) |
1083 °C (Cu melting point, practical limit ~950 °C) |
|
Emergency overload temp. |
250 °C (short term, mineral insulation stable) |
|
Fire survival temp. |
950 °C for ≥ 180 min (BS 6387 CWZ) |
|
Water resistance |
Excellent (copper sheath is impermeable) |
|
Radiation resistance |
Excellent |
|
Weather resistance |
Excellent (copper sheath + LSZH outer) |
|
Flame retardant |
Inherent — non-combustible insulation & copper sheath |
|
Smoke density |
Zero (LSZH outer sheath) |
|
Halogen content |
Zero (mineral insulation + LSZH) |
|
Parameter |
Value |
Note |
|---|---|---|
|
Rated voltage U₀/U |
0.6 / 1 kV |
GB/T 13033 / IEC 60702 |
|
Max. system voltage Uₘ |
1.2 kV |
— |
|
Test voltage AC (5 min) |
3.5 kV |
Routine test |
|
DC resistance @20 °C (50 mm²) |
≤ 0.387 Ω/km |
GB/T 3956 Class 2 Cu max |
|
DC resistance @20 °C (25 mm²) |
≤ 0.727 Ω/km |
GB/T 3956 Class 2 Cu max |
|
AC resistance @90 °C (est., 50 mm²) |
≈ 0.493 Ω/km |
per core |
|
AC resistance @90 °C (est., 25 mm²) |
≈ 0.924 Ω/km |
earth core |
|
Capacitance (approx.) |
negligible |
mineral insulation (near-zero permittivity) |
|
Inductive reactance (approx.) |
≈ 0.07 Ω/km |
at 50 Hz, 5-core |
|
Current rating in air (30 °C) |
160 A |
3-phase loaded, 4×50 mm² (derated for 5-core) |
|
Current rating buried (20 °C) |
135 A |
direct buried (copper sheath excellent heat dissipation) |
|
Current rating in conduit (30 °C) |
125 A |
3-phase, 5-core |
|
Short-circuit current (1 s, Cu, 250 °C) |
≈ 5.0 kA (5000 A) |
50 mm² Cu |
|
Frequency |
50/60 Hz AC |
— |
Reference values: 50 mm² Cu at 160 A, 3-phase 400 V → max balanced load ≈ 110 kVA. Voltage drop at 160 A ≈ 78.9 V/km per core (≈3.2% per 100 m at 400 V).
4. Thermal & Fire. 105 °C continuous conductor temperature (MgO allows higher than XLPE/PVC); short-circuit 250 °C; fire rating 950 °C / 180 min per BS 6387 class C — the cable remains energised during fire with impact and water spray. Zero toxic gas emission, zero halogen.
|
Property |
Value |
|---|---|
|
Max. conductor operating temp. |
90 °C (continuous, termination limited) |
|
Max. short-circuit temp. (≤5 s) |
1083 °C (Cu melting point; practical 950 °C) |
|
Emergency overload temp. |
250 °C (mineral insulation stable) |
|
Min. installation ambient temp. |
−20 °C (LSZH sheath, flexible design) |
|
Service ambient range |
−20 °C to +90 °C (continuous); 950 °C fire survival |
|
Fire survival |
BS 6387 Category CWZ — circuit integrity ≥ 180 min at 950 °C, water jet test (W), mechanical impact (Z) |
|
Property |
Value / Requirement |
|---|---|
|
Flame retardant |
Inherent — non-combustible (mineral insulation + copper sheath) |
|
Halogen content |
Zero (mineral ceramic + LSZH sheath) |
|
Smoke density |
Zero (IEC 61034, LSZH) |
|
Corrosivity |
Non-corrosive (IEC 60754) |
|
Fire survival (circuit integrity) |
BS 6387 CWZ — passes C (950 °C, 180 min), W (water jet during fire), Z (mechanical impact during fire) |
|
Toxicity |
Zero (inorganic materials) |
|
Heat release |
Near zero (non-combustible) |
BS 6387 Classification:
|
Category |
Test Condition |
BTTRZ Result |
|---|---|---|
|
C |
950 °C, 180 min, circuit integrity |
✅ Pass |
|
W |
Water jet during fire test |
✅ Pass |
|
Z |
Mechanical impact during fire test |
✅ Pass |
5. Installation Practice & Handling. CRITICAL: install special MgO end seals at both ends — MgO is hygroscopic and absorbs moisture. Bend ≥ 12 × OD ≈ 460 mm fixed. Use Cu compression lugs + end sealing kits. The Cu tube is the primary fire barrier; the thin PVC outer sheath is only for corrosion protection.
|
Parameter |
Value |
Remarks |
|---|---|---|
|
Minimum bending radius |
≥ 6 × OD → ≈ 198 mm at Ø33 mm |
flexible mineral cable |
|
Max. pulling tension |
5000 N |
Cu conductor + Cu sheath |
|
Direct burial |
Excellent (copper sheath impermeable, no water ingress) |
— |
|
Conduit ID |
≥ 1.5 × OD → ≥ 50 mm; use 63 mm or 75 mm |
— |
|
Fixing |
copper-compatible clamps, cable ties |
avoid galvanic corrosion with steel |
|
Impact resistance |
High (copper sheath provides mechanical protection) |
— |
|
Water resistance |
Excellent (gas-tight copper sheath) |
suitable for submerged/wet |
|
UV resistance |
Excellent (copper sheath + LSZH) |
outdoor exposed |
|
Termination note |
Specialised MI cable terminations required — pot-type seals, compression glands, ceramic terminals |
requires trained installer; cold-shrink or heat-shrink terminations available |
6. Typical Service Applications. Fire pump power supply, emergency lighting circuits, smoke control systems, fire alarm circuits, evacuation signalling, critical life-safety power — any circuit that must remain operational during a fire.
7. Testing & QA Regime. Routine: conductor DC resistance, 3.5 kV AC withstand, insulation resistance ≥ 1000 MΩ·km. Type: BS 6387 class C fire test (950 °C / 180 min with impact and water spray), crush resistance, halogen/toxicity test (zero), end seal integrity.
Cable Parameters
| BTTRZ 4×50+1×25 mm² — Flexible Mineral-Insulated (MgO) Fire-Resistant Cu-Sheathed Cable — Full Parameter Sheet | ||||
| Mineral-insulated fire-resistant cable · Cu conductors / MgO insulation / corrugated Cu tube / PVC outer sheath · 4×50 + 1×25 mm² · 0.6/1 kV · 950 °C 3h fire-rated · GB/T 13033 / BS 6387 · finished Ø ≈ 38.5 mm | ||||
| Section | Parameter | Value | Unit | Remarks / Standard |
| 01 · Identification | ||||
| Cable type | BTTRZ (Flexible mineral-insulated Cu-sheathed fire-resistant cable) | — | Fire-resistant / emergency power | |
| Rated voltage (U0/U) | 0.6/1 | kV (Um=1.2 kV) | Fire-rated power circuit | |
| Number of cores | 4×50 + 1×25 | — | 3P+N+PE (PE=25 mm²) | |
| Conductor material | Annealed copper | — | Class 1/2 per GB/T 3956 | |
| Insulation material | Magnesium oxide (MgO) | — | Mineral insulation, 950 °C | |
| Sheath material | Corrugated copper tube + PVC outer | — | Cu tube = fire barrier | |
| Outer sheath colour | Black / red | — | Fire cable identification | |
| Fire rating | 950 °C / 180 min | — | BS 6387 class C | |
| Standard | GB/T 13033 / BS 6387 | — | Mineral-insulated cable | |
| 02 · Conductor (Copper) | ||||
| Conductor type (power cores) | Solid/stranded copper | — | Class 1/2 per GB/T 3956 | |
| Conductor area (power) | 4 × 50 | mm² | L1/L2/L3/N | |
| Conductor area (PE) | 1 × 25 | mm² | Protective earth | |
| DC resistance @ 20 °C (50 mm²) | ≤ 0.387 | Ω/km | Max per GB/T 3956 | |
| DC resistance @ 20 °C (25 mm²) | ≤ 0.741 | Ω/km | PE core | |
| Conductor weight per km | ≈ 2240 | kg/km | 4×50 + 1×25 Cu | |
| 03 · Insulation & Sheath | ||||
| Insulation type | Magnesium oxide (MgO) powder | — | Mineral, non-combustible | |
| Insulation thickness (around conductor) | ≈ 1.5 | mm | MgO compacted | |
| Copper tube wall | ≈ 0.9 | mm | Corrugated, continuous weld | |
| Outer PVC sheath | ≈ 1.0 | mm | Corrosion protection | |
| Finished outer diameter | ≈ 38.5 | mm | Cu tube + PVC | |
| 04 · Electrical | ||||
| Rated voltage (AC) | 0.6/1 | kV | Fire-rated power | |
| DC resistance @ 20 °C (50 mm²) | ≤ 0.387 | Ω/km | Power cores | |
| Insulation resistance | ≥ 1000 | MΩ·km | MgO — very high | |
| Routine test voltage (AC) | 3.5 kV / 5 min | — | Power-frequency | |
| Fire circuit test | 950 °C / 180 min | — | Cable remains energised | |
| Circuit integrity | BS 6387 class C | — | 950 °C, no circuit failure | |
| 05 · Thermal & Fire | ||||
| Max continuous conductor temp. | 105 | °C | MgO — higher than XLPE | |
| Short-circuit temp. | 250 | °C | Cu conductor limit | |
| Fire rating | 950 | °C / 180 min | BS 6387 class C | |
| Flame spread | None | — | MgO + Cu tube non-combustible | |
| Toxic gas emission | None | — | Mineral — no halogen | |
| Halogen-free | Yes | — | MgO mineral, no halogen | |
| Water resistance | Good | — | Cu tube is water-tight | |
| 06 · Mechanical | ||||
| Min bending radius (fixed) | ≥ 12 × OD ≈ 460 | mm | Corrugated Cu tube | |
| Min bending radius (flexed) | ≥ 15 × OD ≈ 580 | mm | Repeated flexing | |
| Crush resistance | Excellent | — | Cu tube is rigid | |
| Outer sheath | PVC corrosion protection | — | Cu tube main protection | |
| 07 · Ampacity | ||||
| Air ampacity (4×50 loaded) | ≈ 175 | A | 30 °C (est.) | |
| Buried ampacity | ≈ 185 | A | Direct burial | |
| Fire circuit derating | 80% | — | For fire-rated circuits | |
| 08 · Installation | ||||
| Laying methods | Tray, conduit, vertical riser, fire-rated enclosure | — | Emergency power | |
| Terminations | Special mineral cable end seals | — | Critical — must seal MgO | |
| Connectors | Cu lugs + end sealing kits | — | Moisture barrier required | |
| Special tools | MgO cable end sealing kit | — | Moisture-proof termination | |
| 09 · Packing | ||||
| Standard supply length | 100 m / drum | m | Fire cable | |
| Reel / packing type | Wooden drum, sealed ends | — | Ends must be sealed | |
| Surface marking | BTTRZ, 4×50+1×25, 0.6/1kV, 950°C, metre marks | — | Continuous printing | |
| Storage conditions | Dry, indoor, sealed ends | — | MgO is hygroscopic | |
| 10 · Applications | ||||
| Typical use | Fire pump power, emergency lighting, smoke control, fire alarm circuits, evacuation systems, critical life-safety circuits | — | Fire-rated emergency power | |
| Max system voltage | 1.2 | kV (Um) | 0.6/1 kV rated | |
| Fire duration | 950 °C / 180 min | — | BS 6387 class C | |
Test Parameters
| Test Parameters — BTTRZ 4×50+1×25 mm² | ||||
| No. | Test Item | Test Condition / Method | Requirement | Type |
| 1 | Conductor DC resistance | GB/T 3956, 20 °C | ≤ 0.387 Ω/km (50mm²), ≤ 0.741 Ω/km (25mm²) | Routine |
| 2 | Power-frequency withstand | 3.5 kV AC, 5 min | No breakdown | Routine |
| 3 | Insulation resistance | 500 V DC, between Cu tube and conductor | ≥ 1000 MΩ·km | Routine |
| 4 | Fire resistance test | BS 6387 class C: 950 °C, 180 min | Cable remains energised, no circuit failure | Type |
| 5 | Impact test during fire | BS 6387: mechanical impact at flame | Circuit remains intact | Type |
| 6 | Water spray during fire | BS 6387: water spray at flame | Circuit remains intact | Type |
| 7 | Crush test | Cu tube crush resistance | No conductor exposure | Type |
| 8 | Dimensional check | Micrometer | OD ≈ 38.5 mm, Cu tube ≈ 0.9 mm | Routine |
| 9 | End seal integrity | Visual + insulation resistance | Moisture-proof seals | Routine |
| 10 | Corrugation check | Visual | Uniform corrugated Cu tube | Routine |
| 11 | Conductor continuity | Per GB/T 3956 | All 5 cores continuous | Routine |
| 12 | Toxicity / halogen test | IEC 60754 / IEC 60754-2 | Zero halogen, zero toxic gas | Type |
Cable Cross Section Structure
| BTTRZ 4×50+1×25 mm² — Cross-Section Construction Diagram (Schematic) | |||||
| Fire-resistant cable: Cu conductors → MgO mineral insulation → corrugated Cu tube (fire barrier) → PVC outer sheath · 0.6/1 kV · 950 °C / 180 min · finished Ø ≈ 38.5 mm | |||||
| No. | Layer | Material / Construction | Nominal Thickness (mm) | Diameter (mm) | Function / Remarks |
| 1 | Conductors (×5) | Copper: 4×50 mm² (L1/L2/L3/N) + 1×25 mm² (PE) | — | ≈ 9.5 / 6.3 | R ≤ 0.387 / 0.741 Ω/km |
| 2 | MgO mineral insulation | Magnesium oxide (MgO) powder, compacted | ≈ 1.5 around each | — | Non-combustible, 950 °C rated |
| 3 | Corrugated Cu tube | Continuous welded corrugated copper | ≈ 0.9 | ≈ 36.5 | Fire barrier, water-tight, crush-resistant |
| 4 | Outer PVC sheath | PVC, black/red (corrosion protection) | ≈ 1.0 | ≈ 38.5 (finished) | Protects Cu tube from corrosion |
| Key Dimensions & Properties (expanded) | |||||
| Finished cable diameter | ≈ 38.5 | mm | Cu tube + PVC sheath | ||
| Approx. cable mass | ≈ 3850 | kg/km | Cu conductors + MgO + Cu tube + PVC | ||
| Nominal voltage rating | 0.6/1 | kV | Fire-rated power circuit | ||
| Max continuous conductor temp. | 105 | °C | MgO mineral insulation | ||
| Fire rating | 950 | °C / 180 min | BS 6387 class C | ||
| Short-circuit temp. | 250 | °C | Cu conductor limit | ||
| Min bending radius (fixed) | ≥ 12 × OD ≈ 460 | mm | Corrugated Cu tube | ||
| DC resistance @ 20 °C (50 mm²) | ≤ 0.387 | Ω/km | Power cores | ||
| DC resistance @ 20 °C (25 mm²) | ≤ 0.741 | Ω/km | PE core | ||
| Insulation resistance | ≥ 1000 | MΩ·km | MgO — very high | ||
| Routine test voltage (AC) | 3.5 kV / 5 min | — | Power-frequency withstand | ||
| Air ampacity @ 30 °C | ≈ 175 | A | 4 cores loaded (est.) | ||
| Halogen-free | Yes | — | MgO mineral, no halogen | ||
| Toxic gas emission | None | — | Non-combustible mineral | ||
| Schematic — not to exact scale. Finished Ø ≈ 38.5 mm and weight ≈ 3850 kg/km from cross-referenced industry samples. BTTRZ is a flexible mineral-insulated (MgO) copper-sheathed fire-resistant cable — copper conductors embedded in compacted magnesium oxide powder, enclosed in a continuous corrugated copper tube. Unlike RVV-5×4.0 (PVC 70 °C, 300/500 V, 25 A, 350 kg/km, 5-core flexible PVC), BTTRZ uses MgO mineral insulation (950 °C fire-rated), a rigid copper tube sheath (fire barrier), and is designed for emergency power circuits that must survive fire. The Cu tube itself is the fire barrier — it does not burn, does not emit toxic gas, and maintains circuit integrity at 950 °C for 3 hours. Special end seals are required to keep MgO dry. Values marked (est.) require confirmation against the factory test certificate. | |||||
Construction Description
| Construction Description — BTTRZ 4×50+1×25 mm² (mineral-insulated fire cable) | |||
| Layer-by-layer fire-resistant cable: Cu conductors / MgO mineral insulation / corrugated Cu tube (fire barrier) / PVC outer sheath · 0.6/1 kV · 950 °C / 180 min · finished Ø ≈ 38.5 mm | |||
| 1. Product Identity & Ratings | |||
| BTTRZ 4×50+1×25 is a flexible mineral-insulated (MgO) copper-sheathed fire-resistant cable rated 0.6/1 kV, built and tested per GB/T 13033 / BS 6387. It has 4 power cores (50 mm², L1/L2/L3/N) + 1 PE core (25 mm²), all embedded in compacted magnesium oxide powder inside a continuous corrugated copper tube. The cable maintains circuit integrity at 950 °C for 180 minutes. Unlike RVV-5×4.0 (PVC 70 °C, 300/500 V, 25 A, 350 kg/km), BTTRZ is a fire-rated emergency power cable. Finished Ø ≈ 38.5 mm, mass ≈ 3850 kg/km, wooden drums. | |||
| 2. Copper Conductors (4×50 + 1×25) | |||
| The 4 power cores use 50 mm² copper conductors (R ≤ 0.387 Ω/km), and the PE core uses 25 mm² copper (R ≤ 0.741 Ω/km). Conductors are solid or stranded per GB/T 3956. All 5 cores are embedded in MgO mineral powder inside the copper tube. The copper conductors themselves can survive temperatures far above PVC/XLPE cables because MgO does not melt or burn. | |||
| 3. MgO Mineral Insulation | |||
| Magnesium oxide (MgO) is a non-combustible mineral powder compacted around each conductor. Unlike PVC or XLPE (which burn, melt, and release toxic gas), MgO remains stable at 950 °C. This is the core advantage of mineral-insulated cables — the insulation itself does not burn. MgO is hygroscopic, so the cable ends must be sealed with special end seals to prevent moisture ingress. | |||
| 4. Corrugated Copper Tube (Fire Barrier) | |||
| The MgO-insulated conductors are enclosed in a continuous welded corrugated copper tube (≈ 0.9 mm wall). The copper tube serves three functions: (1) fire barrier — copper does not burn; (2) water-tight seal — protects MgO from moisture; (3) mechanical protection — crush-resistant. The corrugations allow some flexibility while maintaining the seal. This is fundamentally different from RVV's PVC outer sheath, which melts and burns. | |||
| 5. Site Handling & Operational Notes | |||
| • CRITICAL: Install special MgO end seals at both ends — MgO is hygroscopic and will absorb moisture if unsealed. • Bend radius 12×OD (≈ 460 mm) fixed. • Fire rating: 950 °C / 180 min (BS 6387 class C). • Use Cu compression lugs + end sealing kits. • PVC outer sheath is for corrosion protection only — the Cu tube is the primary barrier. • At 3850 kg/km, supplied on heavy wooden drums. • Store with ends sealed. • For fire pump, emergency lighting, smoke control circuits. |
8. Cable Structure Display
9. Packaging, Storage & Logistics. 100 m per wooden drum with sealed ends. Continuous marking: BTTRZ, 4×50+1×25, 0.6/1 kV, 950 °C, GB/T 13033, metre marks. Store dry, indoor, with factory end seals intact.
10. Procurement Specification. State "BTTRZ 4×50+1×25, 0.6/1 kV, 950 °C/180 min" + length. Order matching end sealing kits. Confirm against factory fire test certificate. Do not substitute ordinary YJV for fire-rated circuits.
11. Cable Industry FAQ.
Company Details
Business Type:
Manufacturer,Exporter,Trading Company
Year Established:
2009
Total Annual:
50000000-100000000
Employee Number:
260~300
Ecer Certification：
Verified Supplier
Company Profile — Anhui Tongdu Cable Co., Ltd. Company Overview Anhui Tongdu Cable Co., Ltd. (hereinafter "Tongdu Cable") is a professional wire and cable manufacturer headquartered in Zongyang Economic Development Zone, Anhui Province, China. Founded in 2009, the company has grown into one of... Company Profile — Anhui Tongdu Cable Co., Ltd. Company Overview Anhui Tongdu Cable Co., Ltd. (hereinafter "Tongdu Cable") is a professional wire and cable manufacturer headquartered in Zongyang Economic Development Zone, Anhui Province, China. Founded in 2009, the company has grown into one of...
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