NYY, N2XY and N2XH can all be candidates for an industrial power supply. They are not interchangeable solely because their voltage rating and conductor size match. Their insulation, outer sheath and permitted installation conditions differ.
The power cables compared here have a rated voltage of 0.6/1 kV. Start by dividing the route into its actual conditions: inside a building, outdoors, in soil or in water.
Three basic types and their materials
| Cable type | Core insulation | Outer sheath | Installation note |
|---|---|---|---|
| NYY | PVC | PVC | Suitable for installation including soil, water and concrete |
| N2XY | Cross-linked polyethylene (XLPE) | PVC | Also intended for direct burial |
| N2XH | XLPE | Halogen-free compound | Not for direct installation in soil or water |
N2XH can be installed outdoors with protection against direct sunlight. For an underground section, the selected construction must suit the conditions there. A conduit alone does not make a cable suitable for underground installation.
See our power cable range for the conditions that apply to each version and size.
The effect of XLPE insulation
Insulation affects the permissible conductor temperature. XLPE-insulated versions can have a higher permissible conductor temperature than PVC-insulated types. This does not give them a single current rating that applies to every route.
Electrical design determines the required conductor size, taking account of installation method, surroundings, grouping and other relevant conditions. Terminations and equipment must also suit the temperatures used in the design. Changing from NYY to N2XY does not replace that calculation.
Concentric conductors and other versions
Our range also includes NYCY, NYCWY, N2XCY and N2XCH. These constructions have an additional concentric conductor. Specify its construction and cross-section explicitly; the size of the main conductors alone does not describe it.
Other versions differ in armour or outer sheath. Check these features separately. An FR version with a PVC sheath does not become halogen-free simply because its designation includes FR.
The J and O identifiers also matter. In these cable types, they distinguish versions with and without a green/yellow core respectively. Use the complete designation in an enquiry.
Specify fire performance separately
Halogen-free materials, low smoke emission and circuit integrity describe different properties. If a project calls for a particular fire class or circuit integrity, the selected version needs the corresponding evidence.
For a cable enquiry, send the proposed type, number of cores, conductor size and length, together with the installation conditions. Include the existing data sheet when replacing a cable. We can then compare the complete constructions, including their installation limits.