N2XBY – YJV22 (CU/XLPE/STA/PVC) Multi Core

Multi core N2XBY Cable is designed as a steel-tape armoured low-voltage power cable for three-phase distribution circuits in fixed installations where additional mechanical protection is required. It consists of three copper conductors, individually XLPE insulated and identified by colour, laid up together with non-hygroscopic fillers, covered by an inner PVC bedding, double steel-tape armour and a PVC outer sheath. The cable can be installed in tunnels, ducts, conduits, in masonry or directly buried in ground, including stony soils, industrial sites and routes with rodent risk.

Cable Construction

• Conductor: Plain annealed copper, class 1 (solid) or class 2 (stranded), constructed according to IEC 60228.
• Insulation: Extruded cross-linked polyethylene (XLPE), suitable for a maximum conductor temperature of 90 °C in normal operation.
• Core identification: By colour according to VDE 0293-308 (typical arrangement: brown / black / grey, plus green-yellow for the protective earth conductor in N2XBY-J).
• Laid-up cores: Three insulated cores cabled together with non-hygroscopic fillers to form a substantially circular cross-section.
• Inner covering (bedding): Extruded PVC applied over the laid-up cores, providing a bed for the armour.
• Armour: Two helically-applied steel tape layers, with the outer tape approximately centred over the gap of the inner tape, in accordance with IEC 60502-1 Clause 12.7.
• Outer sheath: Extruded PVC applied over the armour, providing mechanical, moisture and chemical protection.

N2XBY Cable Designations

For standard Multi core N2XBY cable, the key distinction is the combination of three copper phase conductors with XLPE thermoset insulation, double steel-tape armour and a PVC outer sheath, rated at 0.6/1 kV (U_m = 1.2 kV) in accordance with IEC 60502-1. The designation N2XBY itself is defined under VDE 0276-603 in the German cable nomenclature system.

In a Multi core armoured construction, the alternating currents of the three phases sum to zero, so the magnetic fluxes through the armour are cancelled and no significant eddy-current or hysteresis losses are induced. Ordinary galvanized steel tape can therefore be used for the armour, providing full mechanical protection without the non-magnetic armour requirement that applies to single-core AC cables under IEC 60502-1 Clause 12.2.

Typical Applications

• Three-phase low-voltage power distribution networks up to 0.6/1 kV
• Industrial plants, factories and process facilities requiring mechanical protection
• Substations, switchrooms and main distribution feeders
• Direct burial in stony, uneven or aggressive soil
• Cable tunnels, ducts, conduits and underground cable channels with rodent risk
• Locations exposed to impact, crushing, vibration or heavy mechanical stress

Internationally, Multi core N2XBY is a 0.6/1 kV Multi core steel-tape armoured XLPE/PVC power cable defined under IEC 60502-1, and is often cross-referenced with designations such as CU/XLPE/STA/PVC 3-core and YJV22 3× under the Chinese GB standard.