| Category | Fire Resistant Instrumentation Cable, Unshielded, LSZH 2×2.5mm² |
| Conductor | 2.5mm² (14 AWG) Stranded Bare Copper, 49/0.24mm |
| Insulation | Silicone Insulation, 100% coverage |
| Jacket | LSZH, Orange |
| Standards | IEC 60331-1, IEC 60332-1, CNS 11175, EN 50200, EN 61034-2, BS 5839-1, BS 6387 |
| Certifications | ISO 9001, RoHS Compliant |
| Packaging | 500m / Reel |
Heizka’s Fire Resistant Cable Unshielded, LSZH 2×2.5mm² is a silicone-insulated instrumentation cable purpose-built for fire alarm and life-safety circuits that must keep signaling through a fire event. Built with 2.5mm² (14 AWG) stranded bare copper conductors and a silicone insulation system rated for sustained high-temperature exposure, it maintains circuit continuity under flame without the added bulk or cost of a metallic shield.
As an unshielded solution, it is the right choice for fire alarm control panels, addressable detector loops, signaling devices, and other life-safety electronic equipment installed away from major sources of electromagnetic interference, especially on longer circuit runs where the larger 2.5mm² conductor keeps voltage drop and DC resistance low. Every reel is manufactured and tested to ISO 9001 quality standards and to IEC 60331-1, IEC 60332-1, EN 50200, EN 61034-2, BS 5839-1, and BS 6387 for fire-resistant circuit integrity, and is backed by Heizka’s multi-year warranty for long-term field performance.
Features
- ✓Purpose-built for fire alarm systems and signaling devices
- ✓Unshielded twisted pair construction for simpler, lower-cost termination
- ✓Silicone insulation for high heat and fire resistance
- ✓2.5mm² (14 AWG) stranded bare copper conductors for longer circuit runs and higher signaling current
- ✓LSZH jacket – halogen-free, low-smoke flame retardant
- ✓Rated voltage 300V
- ✓Continuous footage markers printed on the cable jacket
- ✓Designed for indoor and residential fire-safety installations
- ✓Designed in the USA
- ✓Packaging: 500m/Reel
Standard Compliance
- IEC 60331-1 (Circuit Integrity)
- IEC 60332-1 (Flame Propagation)
- CNS 11175
- EN 50200 (Fire Resistance, Alarm Circuits)
- EN 61034-2 (Smoke Density)
- BS 5839-1
- BS 6387 (Fire Resistance Characteristics)
Ordering Information
| Item # | Description |
|---|---|
| HER25U2LZ | Fire Resistant Instrumentation Cable 2×2.5mm² (14AWG), Unshielded, Twisted Pair, Orange, LSZH, 500m/Reel |
Technical Specifications
Construction / Dimensions
| No. of code | 2 Core |
| Conductor material | Stranded Bare Copper |
| Conductor construction | 2.5mm²; 49/0.24±1%D mm |
| Insulation material | Silicone Insulation (100% coverage) |
| Insulation thickness / diameter | 0.6mm ± 0.05mm / 3.1mm ± 0.10mm |
| Jacket material | LSZH, Orange |
| Jacket thickness / diameter | 0.9mm ± 0.1mm / 8.0mm ± 0.3mm |
Electrical Characteristics
| Max. conductor DC resistance (20°C) | 7.98 Ω/km |
| Dielectric strength (insulation) | 2000V |
Mechanical Characteristics
| Operating temperature | -20°C ~ +200°C |
| Elongation at break | 150% |
| Tensile strength | 10N/mm² |
| Voltage rating | 300V |
Fire Resistant Cable Unshielded 2×1.0mm² vs 2×1.5mm² vs 2×2.5mm² — Which One Do You Need?
| Feature | 2×1.0mm² Unshielded | 2×1.5mm² Unshielded | 2×2.5mm² Unshielded (this cable) |
|---|---|---|---|
| Item # | HER10U2LZ | HER15U2LZ | HER25U2LZ |
| Conductor size (AWG) | 18 AWG | 16 AWG | 14 AWG |
| Conductor construction | 1.0mm² (16/0.24mm) | 1.5mm² (30/0.24mm) | 2.5mm² (49/0.24mm) |
| Jacket diameter | 5.6 ± 0.3mm | 6.6 ± 0.3mm | 8.0 ± 0.3mm |
| Max. conductor DC resistance | 21.4 Ω/km | 12.33 Ω/km | 7.98 Ω/km |
| Best for | Compact detector/signaling loops, shorter runs | Standard fire alarm and detector wiring | Longer fire-alarm circuit runs, higher signaling current |
Frequently Asked Questions
It is designed for fire alarm systems, signaling devices, and electronic equipment in indoor and residential installations, carrying power and signal to detectors, sounders, and control panels on life-safety circuits, particularly on longer circuit runs.
Unshielded twisted pair suits installations where the run is routed away from major EMI sources such as VFDs, high-voltage feeders, or large motors, and where panel design already provides adequate noise immunity. It reduces cost and simplifies termination compared with a shielded equivalent while retaining the same fire-resistant circuit integrity.
The three variants share the same unshielded, silicone-insulated, LSZH construction and differ only in conductor size. The 2×2.5mm² (14AWG) version suits longer circuit runs or higher current draw; the 2×1.5mm² (16AWG) is the standard choice for typical fire alarm and detector wiring; the 2×1.0mm² (18AWG) is the most compact choice for shorter detector and signaling loops.
Yes. It is manufactured and tested to IEC 60331-1, IEC 60332-1, EN 50200, EN 61034-2, BS 5839-1, and BS 6387, the standards commonly required for fire alarm and life-safety circuit integrity cables.
Standard packaging is 500m per reel with continuous footage markers on the jacket. The cable is rated for operation from -20°C to 200°C, suitable for typical indoor and residential fire-alarm installation environments.
As a Fire Resistant Cable Unshielded product, every reel of Heizka Fire Resistant Cable Unshielded, LSZH 2×2.5mm² ships as a continuous 500m length with clear footage markers printed along the jacket, ready to route directly into fire alarm control panels, detector loops, and signaling circuits without unnecessary splicing.
Heizka Cable — Designed in the USA, distributed in 20+ countries worldwide.
