XLPE Steel Wire Armored Power Cable

High Tensile Strength for Vertical Installations

The helical wire construction provides the cable with significant tensile strength — the armour wires carry the cable’s weight load in vertical shafts, mine risers, and suspended spans. Typical safe working loads are 15 to 30 percent of the cable’s calculated breaking load. For a 4-core 95 mm² YJV32, the armour can support a hanging length of 300 to 500 metres under the cable’s own weight before reaching safe working load limits. Steel tape armour (YJV22) provides essentially no tensile strength — the tape layers separate under longitudinal tension within the first few metres of vertical drop.

Crush Resistance ≥ 1200 N/cm for Buried Use

The wire layer provides radial compressive strength comparable to double steel tape armour — typically 1200 N/cm or higher in the IEC 60502 crush test. For direct burial in rocky or stony soil, the round wire geometry distributes point loads across multiple wires simultaneously, preventing the localised deformation that flat tape armour suffers when a sharp stone edge contacts it. Suitable for direct burial without the concrete-duct protection that steel tape armour often requires in rocky ground.

Twisting Tolerance for Offshore and Marine Use

Helical wire armour tolerates rotational forces that would buckle or delaminate steel tape. Critical for submarine cables laid from cable barges (which introduce twisting during deployment), for cable risers on floating platforms that rotate with wave and wind loading, and for any installation where the cable runs over a sheave or drum during installation or operation. The wire-against-wire contact in the armour layer allows limited inter-wire movement that accommodates torsional forces without structural failure.

LV and MV in the Same Construction Family

The same SWA construction applies at both 0.6/1 kV (IEC 60502-1) and 3.6/6 kV through 26/35 kV (IEC 60502-2). For LV projects with SWA in the specification, supply YJV32 / YJLV32 at 0.6/1 kV rated under BS 5467 or IEC 60502-1. For MV projects, the same designation extends to the voltage class; the triple-extruded XLPE core and copper screen are added internally while the external SWA construction remains the same. This allows projects that span LV and MV distribution to use a single cable family with consistent specification and manufacturer documentation.

Earthing Path via Armour Connection

The galvanised steel wire armour provides a low-resistance earth continuity conductor when bonded to earth at cable terminations. For LV installations, the steel wire armour is typically used as the circuit earth, eliminating the need for a separate earth conductor in many installations. Per BS 7671 and IEC 60364, the armour cross-sectional area must be verified against the circuit’s prospective earth-fault current and disconnection time — for large cable cross-sections, the armour earth path is often adequate; for smaller cables, a supplementary earth conductor may be required.

IEC + BS + VDE + AS/NZS Multi-Market Certified

Production certified to IEC 60502-1 (LV) and IEC 60502-2 (MV) as primary international references, plus BS 5467 (UK LV SWA), BS 6622 (UK MV SWA), DIN VDE 0276-620 (Germany), AS/NZS 5000.1 (Australia/NZ LV), and AS/NZS 1429.1 (Australia/NZ MV). BASEC, KEMA, and SGS test reports available for project acceptance. Dual or triple certification on a single production run is standard practice for projects exporting across multiple regulatory regimes.

SWA cable termination requires proper armour cable glands that grip the steel wire layer circumferentially. The gland body has an internal cone that compresses against the wire layer when the gland nut is tightened — this provides both the mechanical cable anchor (preventing cable pull-out) and the earth-bonding connection for the armour. Do not use standard PVC glands on SWA cable, and do not pigtail the armour wires into a lug — the pigtail connection has high contact resistance and poor mechanical retention. Specify the gland size for the cable OD and the material (brass for standard use, stainless for marine or corrosive environments).

For long cable pulls, use a wire-mesh pulling sock or Kellems grip that grips the outer sheath and transfers the pulling force to the steel wire armour — the armour carries the tensile load during installation, not the conductors. Never pull SWA cable by attaching a pulling line to the conductor ends or to a rope eye joined to the cable core — the tensile force is absorbed by the conductor, stretching it and damaging the XLPE insulation at the conductor-to-insulation interface. For vertical shaft installation, use a grip clamp at the top of the shaft to support the cable weight as each drum length is fed down.

SWA cable minimum bending radius is 15× OD during installation (active pulling, per IEC 60502). Tighter bends kink the steel wires and break them at the contact point with the bend, leaving permanent weak spots in the armour coverage. The armour damage is invisible from outside but leaves the cable mechanically unprotected at the bend. Particularly important at building entry points, cable duct bends, and change-of-direction in cable trenches — use proper cable rollers and large-radius bends, never force the cable around a tight corner by hand.

For cable tray and ladder installations, use armour-compatible cable cleats at the intervals specified by IEC 61914 (cable cleats standard) for the cable weight, short-circuit electromagnetic forces, and cleat spacing. For vertical installations, use grip clamps or mid-span support clamps at regular intervals to prevent the cable from hanging under its own weight from a single termination point. For direct-buried installations, lay the cable in a properly prepared trench with sand or fine-soil bedding, route the cable in a gentle S-curve (snake) to allow for thermal expansion, and use warning tiles or tape above the cable depth to prevent future excavator damage.

Before energising any SWA cable installation: megger-test insulation resistance at 1 kV DC (LV) or 5 kV DC (MV) between every conductor-pair and between each conductor and the armour earth. Expected reading for new cable at 0.6/1 kV is > 1000 MΩ per km; for MV > 1000 MΩ per km at voltage above rated U₀. Readings below 100 MΩ indicate water ingress, insulation damage, or installation faults. Document the megger test results in the project handover — they become the baseline for future maintenance comparisons. For MV cable, also conduct the partial-discharge test as described in the YJLV product page.

The steel wire armour is not watertight — moisture enters the cable easily through the inter-wire spaces when the cable end is left open. Apply heat-shrink end caps or self-amalgamating tape to cable ends immediately after cutting, before moving the cable to the installation location. For SWA cable installed in buried trenches, seal both ends before backfilling regardless of whether final terminations are immediately made — moisture wicking through the insulation during the construction period can degrade the XLPE and reduce service life significantly. This is particularly important in coastal areas with high humidity and in areas with high groundwater table.