N2XRY – YJV72 (CU/XLPE/SWA/PVC) Multi Core

Multi-core N2XRY (YJV72) Cable is designed as a round wire armoured low-voltage power cable for fixed installation in three-phase distribution circuits where high tensile strength, vertical-run support and heavy mechanical protection are required. It consists of multiple copper conductors, individually XLPE insulated and identified by colour, laid up together with non-hygroscopic fillers, covered by an inner PVC bedding, a concentric layer of non-magnetic steel armour wires and a PVC outer sheath. The cable is suitable for cable shafts, vertical risers, mine entries, river crossings, direct burial under traction load, and any installation where the armour must also bear longitudinal mechanical stress.

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 N2XRY-J).
• Laid-up cores: 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: A concentric layer of non-magnetic steel wires (austenitic stainless steel or equivalent non-magnetic alloy), closely applied with a minimum gap between adjacent wires, in nominal diameters of 0.8 / 1.25 / 1.6 / 2.0 / 2.5 / 3.15 mm selected per IEC 60502-1 Table 9.
• Outer sheath: Extruded PVC applied over the armour, providing mechanical, moisture and chemical protection.

N2XRY Cable Designations

For standard multi-core N2XRY (YJV72) cable, the key distinction is the use of a concentric layer of non-magnetic steel armour wires laid over the cabled cores, providing significantly higher tensile strength than tape armour, rated at 0.6/1 kV (U_m = 1.2 kV) in accordance with IEC 60502-1. The designation N2XRY itself is defined under VDE 0276-603 in the German cable nomenclature system, and the equivalent designation under Chinese GB is YJV72, where “72” specifically identifies non-magnetic round wire armour.

In a multi-core armoured construction, the alternating currents of the three phases sum to zero and the magnetic fluxes through the armour are cancelled, so ordinary magnetic steel wire would in principle be acceptable. The use of non-magnetic steel wire across both single-core and multi-core variants ensures a single armour material across the product line, simplifying inventory and ensuring full compliance with IEC 60502-1 Clause 12.2 for any mixed AC application.

Typical Applications

• Three-phase low-voltage power distribution networks up to 0.6/1 kV
• Vertical cable runs and shafts where the armour must bear the cable’s own weight
• Cable risers in high-rise buildings, mine entries and offshore structures
• Direct burial in soils subject to settlement, traction or longitudinal stress
• River, road and railway crossings requiring high tensile load capacity
• Industrial plants, substations and main distribution feeders requiring heavy mechanical protection

Internationally, multi-core N2XRY is a 0.6/1 kV multi-core round-wire armoured XLPE/PVC power cable defined under IEC 60502-1, and is most commonly cross-referenced with the Chinese GB designation YJV72 (CU/XLPE/SWA/PVC) where SWA denotes single-wire armour.