Quick Specs
| Category | Fire Resistant Instrumentation Cable, Unshielded, LSZH 2×1.0mm² |
| Conductor | 2 × 1.0mm² (18 AWG) Stranded Bare Copper, Twisted Pair |
| Jacket | LSZH, Orange |
| Standards | IEC 60331-1BS 6387 |
| Packaging | 500m / Reel |
Heizka’s Fire Resistant Cable Unshielded, LSZH 2×1.0mm² is a compact circuit-integrity instrumentation cable engineered to keep fire alarm and signaling circuits alive during a fire event — not just resist ignition. Built with stranded bare copper conductors and a silicone insulation system that retains its dielectric properties at extreme temperatures, it maintains circuit continuity under direct flame exposure without the added bulk of a metallic shield.
This unshielded 1.0mm² version is the right choice for fire alarm control panels, signaling devices, and other life-safety electronic equipment installed on shorter runs or in space-constrained conduit where a full shield isn’t required. Every reel is manufactured and tested to IEC 60331-1 circuit integrity, IEC 60332-1 flame propagation, EN 50200, and BS 6387 fire-resistance standards, carries a halogen-free low-smoke LSZH jacket for safer evacuation routes, and is produced under an ISO 9001 quality system and backed by Heizka’s multi-year warranty for long-term field performance.
Features
- ✓Twisted pair construction for balanced signal transmission
- ✓Silicone insulation retains flexibility and dielectric strength under fire-event temperatures
- ✓Circuit integrity maintained under direct flame exposure per IEC 60331-1 and BS 6387
- ✓Halogen-free, low-smoke LSZH jacket (Orange) for safer means-of-egress routing
- ✓2 × 1.0mm² (18 AWG) stranded bare copper conductors, twisted pair
- ✓Sequential footage markers printed on jacket to reduce installation waste
- ✓Rated 300V for fire alarm, signaling, and electronic equipment circuits
- ✓Packaging: 500m/Reel
Standard Compliance
- ISO 9001
- RoHS Compliant
- IEC 60331-1 (Circuit Integrity)
- IEC 60332-1 (Flame Propagation)
- EN 50200 (Fire Resistance, Alarm Circuits)
- EN 61034-2 (Smoke Density)
- BS 5839-1
- BS 6387 (Fire Resistance Characteristics)
Ordering Information
| Item # | Description |
|---|---|
| HER10U2LZ | Fire Resistant Instrumentation Cable, Unshielded, 2×1.0mm² (18AWG), Twisted Pair, LSZH, Orange, 500m/Reel |
Technical Specifications
Construction / Dimensions
| No. of Cores | 2 Core |
| Conductor material | Stranded Bare Copper |
| Conductor construction | 1.0mm²; 16/0.24 ± 1%D mm |
| Insulation material | Silicone Insulation, 100% coverage |
| Insulation thickness / diameter | 0.5mm ± 0.05mm / 2.1 ± 0.10mm |
| Jacket material | LSZH (Orange) |
| Jacket thickness / diameter | 0.7mm ± 0.1mm / 5.6 ± 0.3mm |
Electrical Characteristics
| Max. conductor DC resistance (20°C) | 21.4 Ω/km |
| Dielectric strength (insulation) | 2000V |
Mechanical Characteristics
| Operating temperature | -20°C ~ +90°C |
| Elongation at break | 150% |
| Tensile strength | 10 N/mm² |
| Voltage rating | 300V |
*Operating temperature per the construction shared across Heizka’s unshielded fire-resistant instrumentation cable series (2×1.5mm² and 2×2.5mm² variants); not separately re-printed on this SKU’s catalogue page.
1.0mm² vs 1.5mm² vs 2.5mm² Unshielded — Which One Do You Need?
| Feature | 2×1.0mm² Unshielded (this cable) | 2×1.5mm² Unshielded | 2×2.5mm² Unshielded |
|---|---|---|---|
| Item # | HER10U2LZ | HER15U2LZ | HER25U2LZ |
| Conductor cross-section | 1.0mm² (16/0.24mm) | 1.5mm² (30/0.24mm) | 2.5mm² (49/0.24mm) |
| AWG equivalent | 18 AWG | 16 AWG | 14 AWG |
| Max. DC resistance (20°C) | 21.4 Ω/km | 12.33 Ω/km | 7.98 Ω/km |
| Overall jacket diameter | 5.6 ± 0.3mm | 6.6 ± 0.3mm | 8.0 ± 0.3mm |
| Best for | Shortest runs and space-constrained conduit or trunking | Standard-length fire alarm and signaling circuit runs | Longer circuit runs where lower conductor resistance and voltage drop matter |
Frequently Asked Questions
Why choose an unshielded fire resistant cable?
Unshielded twisted pair suits installations where the run is short or 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 installation complexity compared with a shielded equivalent while retaining the same fire-resistant circuit integrity.
What’s the difference between the 2×1.0mm², 2×1.5mm², and 2×2.5mm² Unshielded versions, and which should I choose?
All three share the same silicone insulation and LSZH jacket construction and differ mainly in conductor cross-section. The larger 2.5mm² conductor has lower resistance (7.98 Ω/km) than the 1.5mm² (12.33 Ω/km) or 1.0mm² (21.4 Ω/km) versions, so it’s the better choice for longer circuit runs where voltage drop is a concern; the smaller gauges suit shorter runs and tighter conduit fill.
Which fire-resistance standards does this cable meet?
It is tested to IEC 60331-1 for circuit integrity under fire, BS 6387 for fire resistance characteristics, and EN 50200 for fire-resistant cables required to maintain circuits in alarm systems, alongside IEC 60332-1 flame propagation and BS 5839-1 fire detection and alarm system guidance.
Is this cable low-smoke and halogen-free?
Yes. The LSZH (Low Smoke Zero Halogen) jacket limits smoke density per EN 61034-2 and avoids emitting corrosive halogen gases when burned, which is important for occupant evacuation and equipment protection during a fire event.
What voltage rating and packaging does this cable come in?
The cable is rated for 300V and ships in standard 500m reels, with sequential footage markers printed on the jacket to help track remaining length and reduce waste during installation.
Every Fire Resistant Cable Unshielded, LSZH 2×1.0mm² reel ships in standard 500m lengths with clear footage markings on the jacket, making it easy to plan and track cable usage across fire alarm and signaling circuit installations.
Heizka Cable — Designed in the USA, distributed in 20+ countries worldwide.
