NA2XBY – YJLV22 (AL/XLPE/STA/PVC) Multi Core

Multi core NA2XBY 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 and where reduced cable weight is preferred. It consists of three aluminium 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, utility distribution networks and routes with rodent risk.

Cable Construction

• Conductor: Plain aluminium or aluminium alloy, 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 NA2XBY-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.

NA2XBY Cable Designations

For standard Multi core NA2XBY cable, the key distinction is the combination of three aluminium 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 NA2XBY itself is defined under VDE 0276-603 in the German cable nomenclature system. Compared with copper-conductor N2XBY, NA2XBY offers significantly lower overall cable weight and reduced material cost, which is particularly valuable for armoured cables where the armour layer already adds substantial mass.

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
• Utility distribution feeders requiring mechanical protection
• Industrial plants, factories and infrastructure projects with long cable routes
• Direct burial in stony, uneven or aggressive soil
• Cable tunnels, ducts, conduits and underground cable channels with rodent risk
• Large-section feeders where weight and cost are critical factors

Internationally, Multi core NA2XBY is a 0.6/1 kV Multi core aluminium steel-tape armoured XLPE/PVC power cable defined under IEC 60502-1, and is often cross-referenced with designations such as AL/XLPE/STA/PVC 3-core and YJLV22 3× under the Chinese GB standard.