NF C 15-100: Fire Safety Requirements for Electrical Cables

NF C 15-100 is the French reference standard for low-voltage electrical installations. It covers the design, installation and verification of electrical systems in buildings. For electrical cables, it sets rules for cable selection, conductor sizing, installation methods and environmental conditions. The latest version also places greater emphasis on external influences and fire safety when determining the appropriate cable performance.

The latest version of NF C 15-100 covered in the Nexans white paper was published in August 2024 and has applied since August 2025. One of its key changes is the greater consideration of external influence conditions when specifying electrical cables. Building type alone is no longer sufficient. Evacuation conditions, fire risks, combustible materials and building configuration can all affect the required cable performance.

For ERP buildings covered by the French Order of 17 May 2024, electrical cables must achieve at least Cca-s2,d2,a2 when the building permit or works authorisation was submitted after 23 May 2025. This classification considers fire propagation, smoke production, flaming droplets and smoke acidity. In higher-risk areas or evacuation routes, Cca-s1,d2,a1 may be specified to provide a higher level of fire performance.

Cca-s1,d2,a1 describes the reaction-to-fire performance of an electrical cable. Cca refers to its contribution to fire development and propagation. s1 indicates low smoke production. d2 relates to flaming droplets and particles. a1 indicates a low level of smoke acidity and corrosivity. This Euroclass therefore assesses several fire-safety criteria rather than focusing only on flame propagation.

The main difference between Eca and Cca is the cable’s level of fire performance. Eca corresponds to a basic level mainly related to flame propagation. Cca meets higher requirements concerning the cable’s contribution to fire development and propagation. A Cca classification may also include additional criteria for smoke, flaming droplets and acidity, such as Cca-s1,d2,a1 or Cca-s2,d2,a2.

Under NF C 15-100, external influences describe the actual environment in which an electrical installation is located. They cover conditions that may affect cable specification. BE2 relates to fire risks, BD2 to BD4 cover evacuation conditions, CA2 concerns combustible construction materials and CB2 covers building configurations that can facilitate fire propagation. These conditions may lead to the specification of a higher cable Euroclass.

Yes. NF C 15-100 applies to new installations, extensions, modifications and existing parts of an electrical installation affected by renovation work. A renovation project should therefore distinguish between untouched existing systems, new circuits and modified installations. For each affected area, cable selection should reflect the applicable requirements, the installation environment and any relevant external influence conditions.

Reaction to fire describes how a cable behaves when exposed to fire. It considers factors such as contribution to fire, smoke production, flaming droplets and acidity. Fire resistance describes the ability of a cable or electrical circuit to maintain its function for a given period during a fire. These two concepts address different safety objectives and should not be confused when specifying electrical cables.

A cable Declaration of Performance documents the declared characteristics of an electrical cable, including its reaction-to-fire classification under the CPR framework. It supports product traceability and helps verify that the installed cable matches the project specification. Together with technical data sheets, product markings and project documentation, it also helps demonstrate the compliance of the electrical installation.

Nexans FR-N1X6G3 Protect is classified Cca-s1,d2,a1. This Euroclass exceeds the Cca-s2,d2,a2 minimum required for ERP and IGH projects covered by the latest French fire-safety requirements. It is designed for buildings and areas where reduced smoke production and low smoke acidity are important specification criteria. The cable is available in conductor sizes ranging from 1.5 mm² to 240 mm².