NYY-J is the German-standard unarmoured power cable widely used across Europe for fixed distribution. Copper conductors are PVC insulated, laid up and covered by a heavy black PVC sheath that is thicker and tougher than the sheath on comparable British cables. The 'J' suffix indicates that one core is green and yellow for use as a protective conductor; the 'O' version has no such core.
Key applications
- Fixed power distribution in industrial and commercial buildings
- Supplies to machinery, plant and control panels
- Runs on tray, in ducts, in masonry or clipped to structure
- Imported machinery and process equipment wired to European practice
- Installations specified to DIN or VDE requirements
Features and benefits
- Heavy PVC sheath gives better abrasion and impact resistance than a standard sheathed cable
- Green and yellow protective core included as standard on the J version
- Core identification follows HD 308 S2, so colours match UK harmonised practice
- Wide range of core counts and sizes, including high core counts for control
- Rated 0.6/1 kV, so suitable for three-phase distribution
Specification notes and limitations
This cable is made to a German standard, not a British one. BS 7671 requires equipment to comply with an appropriate standard, and current-carrying capacities in its appendices are tabulated for British cable types, so ratings for NYY-J have to be taken from the manufacturer's own data and justified. There is no armour and no metallic layer, so it offers no mechanical protection beyond the sheath, provides no armour-based protective conductor, and is not suitable for direct burial in the UK without separate mechanical protection such as ducting. The conductor limit is 70 °C, lower than the XLPE armoured cables it is often compared with, and the usual derating applies for grouping, ambient temperature and installation in the ground. Note the relatively large minimum bending radius when planning terminations into enclosures.
