TEBAOFLEX Fire-Resistant LSZH Speaker Cable (300/500 V) is a life-safety emergency voice alarm (EVAC), public-address, and general-alarm (PA/GA) audio cable engineered to maintain uninterrupted circuit integrity at 950°C for 3 hours under BS 6387 Category C. Combining annealed stranded tinned copper conductors, double-layer mica-glass fire barrier tape, thermoset XLPE insulation, and a grey low-smoke zero-halogen (LSZH) outer sheath, it ensures evacuation announcements remain audible while emitting minimal smoke and zero corrosive acid gases.
1. Application Scope & Life-Safety Cable Comparison
Emergency phased-evacuation and industrial PA/GA systems depend on speaker feeders remaining operational long after conventional PVC audio cables melt and short out:
- Emergency Voice Alarm & Evacuation (EVAC / PA-VA): Constant-voltage
70 V / 100 Vloudspeaker zones in metro stations, road/rail tunnels, airports, hospitals, and high-rise commercial complexes. - Industrial, Petrochemical & Power-Plant PA/GA Loops: Audible muster-alarm horns, beacons, and intercom circuits across refineries, LNG terminals, substations, and turbine halls.
- Marine & Offshore Accommodation Modules: Low-smoke halogen-free audio distribution where tinned copper corrosion resistance and zero acid-gas emission protect personnel and sensitive control electronics.
| TEBAOFLEX Safety / Signal Cable | Voltage Rating | Fire / Screen Architecture | Primary System Duty |
|---|---|---|---|
| Fire-Resistant LSZH Speaker — This Page | 300/500 V | Double Mica + XLPE + Grey LSZH (BS 6387 Cat C) | 100 V EVAC voice alarm & PA/GA loudspeaker loops |
| BFOU 0.6/1 kV Offshore Fire Cable | 0.6/1 kV | Mica + EPR + Halogen-Free Mud-Resistant SHF2 | IEC 60331-21 / NEK 606 offshore platform emergency power |
| Shielded Instrumentation Cable | 300/500 V | OS / IS+OS Foil Screen (+ optional SWA / LSZH) | 4–20 mA / HART process telemetry & PLC analog pairs |
| SY LSZH Braided Control Cable | 300/500 V | Galvanized steel wire braid (GSWB) + LSZH | Mechanically protected indoor/plant control interconnections |
2. Cable Construction (Authentic 4-Layer Fire-Survival Build)
Each layer visible in the cutaway is engineered so inorganic fire barriers remain intact even after polymeric layers char during prolonged flame exposure:
950°C.+105°C operating temperature with high insulation resistance (≥ 2,000 MΩ-km); standard polarity pair in Black and White (Red/Black or 4-core A/B zone colour coding available).3. Electrical, Fire-Integrity & Mechanical Characteristics
Routine dielectric, fire-survival, and ageing test requirements for TEBAOFLEX 300/500 V Fire-Resistant LSZH Speaker Cable:
| Test / Parameter | Verified Engineering Requirement |
|---|---|
| Rated Voltage U0/U | 300/500 V |
| AC Dielectric Voltage Test | 2,000 V / min without breakdown |
| Minimum Insulation Resistance (20°C) | ≥ 2,000 MΩ-km |
| Fire-Resistance Circuit Integrity | BS 6387 Category C: no interruption of service at 950°C continuous flame for 3 hours (full BS 6387 CWZ & IEC 60331-21 builds available) |
| Smoke & Halogen Performance | Low-smoke zero-halogen jacket compliant with IEC 60754-1/2 (halogen-free, low acidity) & IEC 61034-2 (high light transmittance) |
| Operating & Installation Temperature | Operating: -20°C to +105°C; installation pulling: -5°C to +75°C |
| Jacket Tensile & Elongation (Unaged) | Tensile strength ≥ 10 MPa; elongation at break ≥ 125% |
| Thermal Ageing Retention & Cold Bend | Aged tensile strength & elongation ≥ 70% of unaged value; cold bend at -20°C for 4 hours with no crack |
4. Dimensional Schedule & 100 V Speaker Loop Sizing Guide
Standard two-core configurations and optional four-core dual-circuit (A+B redundant) PA/GA builds are listed below:
| Part Code | Construction | XLPE Wall (mm) | Core Insulation OD (mm) | LSZH Jacket Wall (mm) | Nominal Overall OD (mm) | Max. Pull Tension (N) | Max. DC Resistance @ 20°C (Ω/km) | Approx. Weight (kg/km) |
|---|---|---|---|---|---|---|---|---|
FR-LSZH-SPK-2X1.5 | 2 × 1.5 mm² | 0.7 | 4.2 | 0.8 | 10.0 | 180 | 12.2 | 112 |
FR-LSZH-SPK-2X2.5 | 2 × 2.5 mm² | 0.8 | 4.8 | 1.0 | 11.6 | 300 | 7.6 | 158 |
FR-LSZH-SPK-2X4.0 | 2 × 4.0 mm² | 0.8 | 5.2 | 1.0 | 12.4 | 400 | 4.7 | 205 |
FR-LSZH-SPK-2X6.0 | 2 × 6.0 mm² | 0.8 | 5.8 | 1.2 | 14.0 | 450 | 3.1 | 282 |
FR-LSZH-SPK-4X1.5 | 4 × 1.5 mm² (Dual A/B) | 0.7 | 4.2 | 1.0 | 12.2 | 360 | 12.2 | 196 |
FR-LSZH-SPK-4X2.5 | 4 × 2.5 mm² (Dual A/B) | 0.8 | 4.8 | 1.1 | 13.8 | 550 | 7.6 | 278 |
100 V Line Emergency Voice Alarm Maximum One-Way Route Length (10% Drop / ≤ 1 dB Loss at 20°C)
| Conductor Cross-Section | Loop DC Resistance (2 × R @ 20°C) | Max. Route @ 100 W Load (100 Ω) | Max. Route @ 200 W Load (50 Ω) | Max. Route @ 500 W Load (20 Ω) |
|---|---|---|---|---|
| 2 × 1.5 mm² | 24.4 Ω/km | 450 m | 225 m | 90 m |
| 2 × 2.5 mm² | 15.2 Ω/km | 720 m | 360 m | 145 m |
| 2 × 4.0 mm² | 9.4 Ω/km | 1,170 m | 585 m | 235 m |
| 2 × 6.0 mm² | 6.2 Ω/km | 1,770 m | 885 m | 355 m |
Fire-Zone Support & Pulling-Tension Note: During conduit installation, never exceed the rated 180–450 N maximum pulling tension so the underlying double mica-glass fire barrier tape is not creased. Fix horizontal and vertical containment runs with stainless-steel fire-rated P-clips and ceramic terminal blocks rather than plastic cable ties. Explore our complete industrial & control cable catalog for companion fire-alarm and control circuits.
5. Frequently Asked Engineering Questions
How does double mica-glass tape keep a speaker circuit working at 950°C?
During a severe building, tunnel, or industrial plant fire, organic XLPE and LSZH polymers eventually pyrolyze into ash above 400–500°C. The overlapping double-layer phlogopite mica-glass tape wrapped directly over each stranded tinned-copper conductor sinters into an inorganic ceramic dielectric shell that prevents conductor-to-conductor short circuits at 950°C for 3 hours under BS 6387 Category C.
What is the difference between fire-retardant LSZH cable and fire-resistant LSZH cable?
A flame-retardant LSZH cable (IEC 60332-1 / IEC 60332-3) restricts flame spread and limits toxic halogen gas, but its circuit fails shortly after direct flame impingement. A fire-resistant LSZH cable adds double mica fire-barrier tapes so emergency voice alarm (EVAC) and PA/GA loudspeakers continue broadcasting evacuation instructions throughout a 3-hour 950°C fire.
How do I size 1.5 mm², 2.5 mm², 4.0 mm², or 6.0 mm² cable for a 100 V line PA/VA speaker loop?
On a 100 V constant-voltage voice alarm line (load impedance Z = 10,000 / Watts), keeping cable loop voltage drop within 10% (approx. 1 dB insertion loss) requires loop resistance R_loop ≤ 0.11 × Z. At 200 W speaker load (50 Ω), 2×1.5 mm² supports up to 225 m, 2×2.5 mm² up to 360 m, 2×4.0 mm² up to 585 m, and 2×6.0 mm² up to 885 m one-way route length at 20°C (apply a 1.35× temperature factor if sizing for hot-fire loop resistance).
Can TEBAOFLEX supply BS 6387 CWZ, foil-screened, or red/orange jacketed versions?
Yes. Beyond the standard unscreened grey LSZH BS 6387 Category C build, we manufacture full BS 6387 Category C, W, Z (950°C flame + water spray + mechanical shock), overall aluminium/PET foil + tinned-copper drain-wire screened PA/GA cables to eliminate 50/60 Hz hum near power trays, and red or orange LSZH jackets for fire-circuit visual segregation.
Why are stranded tinned copper conductors used instead of solid bare copper?
Stranded tinned copper pulls smoothly through tight containment conduits within the rated 180–450 N tension limits, resists moisture and salt-mist oxidation in coastal, tunnel, and offshore plant junction boxes, and avoids brittle copper scaling when exposed to high-temperature fire conditions.
What details should be submitted for a fire-resistant speaker cable quotation?
Send the core count and cross-section (e.g., 2×1.5 mm², 2×2.5 mm², 2×4.0 mm², 2×6.0 mm², or 4-core A/B loop), screening requirement (unscreened or AL/PET foil + drain wire), required fire test standard (BS 6387 Cat C, CWZ, or IEC 60331), outer jacket colour, and total drum or reel quantities.
Request a Factory Quote for Fire-Resistant LSZH Speaker & PA/GA Cable
Submit your speaker zone cross-sections, screening or BS 6387 CWZ / IEC 60331 fire-test specification, sheath colour, and drum quantities. Our engineering team will return a technical datasheet and quotation within 24 hours.
