Power & Safety in One Cable. The FRNC 4x25mm² for Public Infrastructure.
A fire in a public building doesn’t just threaten structural integrity. It threatens life through toxic smoke inhalation and equipment failure through corrosive gas release. These secondary damage mechanisms often cause more long-term disruption than the fire itself. The FRNC Power Cable 4x25mm² eliminates those specific risks. By combining halogen-free materials with flame-retardant properties, this cable keeps evacuation routes survivable and protects sensitive electronic systems during a thermal event. You comply with the strictest EU safety directives without increasing installation complexity or sacrificing electrical performance.
Low-Smoke, Zero-Halogen Compound. Because Smoke Kills Before Fire Does.
Standard PVC jackets release dense, toxic hydrogen chloride gas when they burn. That gas binds with moisture in the eyes, throat, and lungs to form hydrochloric acid. It also corrodes copper circuitry inside building management systems meters away from the fire source.
FRNC compound emits practically no corrosive gas. Smoke density is reduced by over 90% compared to PVC.
You give occupants a real chance to evacuate. Fire crews can locate the source faster. Adjacent switchgear, servers, and HVAC controls survive the event without acid-induced pitting and short circuits. Total building downtime drops from months to days.
Stranded Plain Copper Conductor. Easy Pulling. No Hot Spots.
Solid conductors resist bending. Installers fight the cable on tray bends and in tight service risers. That resistance leads to micro-fractures at termination points. Micro-fractures cause hot spots. Hot spots cause tripped breakers under load.
The Class 2 stranded plain copper conductor in this 4x25mm² configuration stays flexible during installation. It beds down cleanly into lug barrels and terminal blocks.
Installation time per floor drops. Termination reject rates fall to near zero. You avoid the call-back for a thermal imaging survey because the terminations were done right the first time.
0.6/1kV Voltage Rating with CE Compliance. One Specification Across the Project.
Mix-and-match cable specs create confusion on large public builds. A lower-rated cable in one riser creates a liability chain that cascades up to the consulting engineer.
This cable is rated for 0.6/1kV and carries full CE marking under the Construction Products Regulation (CPR). Its Euroclass rating confirms compliance for use in public buildings where reaction-to-fire performance is a legal requirement, not a preference.
One cable spec covers your sub-distribution needs across multiple floors and fire compartments. Your electrical due diligence package passes plan check without amendment cycles.
Core Technical Data
| Parameter | Specification |
|---|---|
| Cable Type | FRNC (Flame-Retardant, Non-Corrosive) Power Cable |
| Nominal Cross-Section | 4 x 25 mm² |
| Conductor Material | Plain Copper, Class 2 Stranded |
| Conductor Shape | Circular Compacted |
| Insulation Material | Cross-Linked Polyethylene (XLPE) |
| Outer Sheath Material | Halogen-Free, Flame-Retardant Thermoplastic Compound |
| Rated Voltage (Uo/U) | 0.6 / 1 kV |
| Maximum Operating Temperature | 90 °C |
| Maximum Short-Circuit Temperature | 250 °C (max. 5 s duration) |
| Minimum Bending Radius (Installation) | Approx. 12 x overall diameter |
| Operating Temperature Range (Flexible) | -5 °C to +50 °C |
| Operating Temperature Range (Fixed) | -30 °C to +70 °C |
| Sheath Colour | Orange (standard), other colours available on bulk order |
| Flame Propagation | IEC 60332-1-2 |
| Smoke Density | IEC 61034-2 (Light transmittance ≥ 60%) |
| Corrosive Gas Emission | IEC 60754-2 (pH value ≥ 4.3, conductivity ≤ 10 µS/mm) |
| CE Marking | Yes (CPR Euroclass Eca minimum, higher classes available on request) |
Where This Cable Is Specified
- High-Rise Commercial Towers. Used in emergency lighting and fire alarm circuits inside shared escape routes. Maintains circuit integrity long enough for phased evacuation protocols while generating minimal smoke.
- Hospitals & Healthcare Facilities. Installed in feeder circuits for life-support systems and imaging equipment. The non-corrosive jacket protects sensitive medical electronics from acidic contamination during a smouldering fire event.
- Airport Terminals & Rail Stations. Runs within crowded concourse sub-floor cable trays. Low-smoke performance prevents disorientation during mass evacuation across large public concourses.
- Data Centres Hosting Public Infrastructure. Connects sub-distribution panels to rack PDUs. The zero-halogen design eliminates the risk of chloride-induced hard drive corrosion, a hidden failure mode that surfaces weeks after minor thermal incidents.
- Educational Campuses. Powers sub-distribution across libraries, lecture halls, and research labs. Meets the public safety mandate required by government tender packages for low fire-load materials.
Compliance & Testing Standards
- ✅ IEC 60502-1 – Power cables with extruded insulation for rated voltages up to 1kV
- ✅ IEC 60332-1-2 – Flame propagation test for a single insulated wire or cable
- ✅ IEC 60754-2 – Determination of halogen acid gas content via pH and conductivity
- ✅ IEC 61034-2 – Measurement of smoke density under fire conditions
- ✅ BS EN 50575 – Construction Products Regulation for power, control and communication cables
- ✅ RoHS Directive 2011/65/EU – Restriction of hazardous substances in cable materials
- ✅ ISO 9001 – Quality management system certification at the manufacturing site
Technical Questions Engineers Ask
Can you supply this cable with a higher Euroclass rating than Eca?
Yes. Eca is the base-level reaction-to-fire classification for this stock cable. We routinely supply B2ca- and Cca-rated versions with additional LSZH sheathing compounds for institutional projects where local building codes demand enhanced fire performance. Lead times for upgraded CPR classes are typically 2–3 weeks added to the standard production window.
What is the actual outside diameter for tray fill calculations?
The nominal overall diameter for the 4x25mm² FRNC cable is approximately 20.5 mm. This figure depends slightly on the sheath thickness tolerance. Use 21 mm for tray fill calculations to stay on the safe side. We supply a dimensional datasheet with each batch test report so you can verify against your as-built cable tray schedule.
How do you terminate this cable to prevent strand breakage?
The Class 2 stranded copper accepts standard compression lugs and mechanical shear-bolt lugs without issue. Strip the XLPE insulation with a rotary tool, not a knife, to avoid nicking the conductor surface. For M10 and M12 busbar connections, we recommend a double-indent crimp using hexagonal dies. We include terminal lug compatibility charts in the packing slip for your site electricians.
Your Project Specification. Shipped.
Sourcing an FRNC cable that passes a bid review is the first hurdle. Getting it on site with full traceability, on the date you need it, is the real challenge. We operate from a dedicated stocking programme for the 4x25mm² FRNC specification. No minimum order quantity cuts from a random drum. You receive sealed, labelled wooden drums with a unique batch certificate linking every metre to its ISO 9001 production run.
Send your project panel schedule or riser diagram to our technical desk. We return a compliance matrix mapping each feeder to our FRNC cable range within one working day. No fee. No obligation beyond starting a conversation about your next public infrastructure build.