NYY vs N2XH cable comes down to materials, fire requirements and the route. NYY uses PVC insulation and a PVC sheath for conventional fixed LV distribution. N2XH normally combines XLPE insulation with a halogen-free sheath system where low-smoke, halogen-free performance is specified. The final choice matches electrical duty, the required fire performance and the indoor, outdoor or buried installation conditions.
NYY vs N2XH: three changes behind the names
Changing from NYY to N2XH changes both insulation and sheath materials. Those changes affect thermal, mechanical and environmental properties, as well as the finished dimensions.
| Srovnávací bod | NYY | N2XH |
|---|---|---|
| Typical fixed-installation rating | 0.6/1 kV | 0.6/1 kV |
| Izolace | PVC | XLPE |
| Vnější plášť | PVC | Halogen-free compound |
| Common maximum continuous conductor temperature | 70°C | 90°C |
| Main comparison advantage | Conventional PVC construction for permitted distribution routes | Halogen-free construction where the specified smoke and fire performance is established |
| What the designation does not establish alone | Any installation environment, fire class or current rating | Any installation environment, fire class or current rating |
The temperatures shown are common conductor operating limits. The product datasheet gives the actual rating, while installation conditions determine ampacity. Dirigentská třída, core arrangement and protective-core provision also remain part of the specification.
The NYY-J fixed-distribution cable includes a green/yellow protective core. An N2XH alternative must preserve the circuit protective-conductor function; the J/O suffix identifies that core arrangement.
Smoke, flame spread and continued operation are different questions
N2XH is often considered because a building specification excludes halogenated cable materials. PVC contains chlorine; replacing PVC components with suitable halogen-free compounds addresses a different question from increasing the insulation temperature rating.
Four properties need to remain separate:
- Halogen acid gases: IEC 60754-1 concerns gases released when cable materials burn. Its public scope addresses material components, not a universal approval of an entire installation.
- Smoke: smoke-density evaluation concerns visibility under defined burning conditions. A halogen-free description alone is not a numerical smoke result.
- Flame propagation: the relevant test addresses how flame spreads under specified conditions. IEC 60332-1-2 covers a single vertical specimen; performance in a group is a separate question.
- Circuit integrity: maintaining electrical operation during a fire requires evidence for that duty. Neither XLPE nor a low-smoke description proves it.
Emergency circuits can require continued power during fire as well as low-smoke materials. These are separate performance requirements, addressed by the specified construction and circuit-integrity tests.
The CPR reaction-to-fire class belongs to the particular product and its declaration of performance. The explanation of CPR classification covers that classification in more detail.
BASEC discusses independent assessment of material suitability alongside electrical, mechanical and environmental requirements. The practical comparison considers all of these, rather than smoke performance in isolation.
Thermal headroom and the installed current rating
A common XLPE conductor limit of 90°C offers thermal headroom compared with a 70°C PVC-insulated design. The useful current-rating difference depends on how the installed cable dissipates heat.
Heat still has to leave the installed cable. Grouped circuits, a hot service space, thermal insulation around the route, soil conditions and the number of loaded cores can change the outcome. Terminals and connected equipment may also have a lower permissible operating temperature than the insulation.
Například, compare hypothetical four-core cables with the same copper area under the same installation method, ambient conditions and loading basis. Open-air and duct ratings describe different thermal environments; the 70°C and 90°C conductor limits are inputs to the assessment.
Matching the cable to each part of the route
A circuit may pass through a service corridor, an outdoor wall and an underground section. The selected construction needs the appropriate fire, exposure and moisture properties for each part of that route.
A protected indoor feeder
Where the project permits PVC and the NYY construction meets the circuit duty, a conventional PVC cable can remain appropriate. Where smoke and halogen requirements exclude that construction, the comparison shifts toward an evidenced halogen-free design. The N2XH halogen-free power cable is the relevant product family, but the particular fire class and installation limits still belong to the selected design.
An exposed outdoor section
Outdoor sections need a cable rated for the sunlight, počasí, temperature and support conditions. The sheath specification establishes the relevant environmental properties.
A buried or persistently wet section
Underground routes use a cable with the specified direct-burial and water-exposure properties, together with the required protection. Check those conditions for the particular NYY or N2XH construction.
Ducts provide mechanical protection but may also collect water. The cable water-resistance requirement is therefore considered alongside drainage, route protection and the intended installation.
When a substitution changes more than the cable
A replacement can change gland sizes, containment space and termination compatibility. Finished diameter, třída vodiče, sheath behaviour and handling limits are checked together so the cable fits the existing equipment and route.
A useful cost comparison matches conductor size, uspořádání jádra, production quantity and supply terms. It also includes any route changes, additional protection or accessory changes caused by the material choice.
NYY remains a practical PVC option where the project permits it. N2XH addresses a low-smoke, halogen-free material requirement. The right choice satisfies the electrical duty, fire specification and route conditions together.
Discuss your NYY or N2XH requirement with XWA. Share the cable size, core arrangement and intended route for a project-specific quotation.