Flexible Single Core Cables: XLPE SDI Power Cable for Switchboards and Public Buildings

Flexible single core cable — known in the Australian market as XLPE SDI (single-double-insulated) cable — pairs XLPE core insulation with a PVC outer sheath over a flexible copper conductor. HELU Australia's range covers a 90°C-rated Flexible XLPE range and a 110°C-rated Flexible SDI range, both designed for use in mains switchboards, submains, and public buildings, with an option of a highly flexible, low-smoke, halogen-free construction available for sensitive occupied spaces.

• Two temperature classes: A 90°C-rated Flexible XLPE range and a 110°C-rated Flexible SDI range for higher-load or higher-ambient applications.
• Highly flexible construction: A finely stranded copper conductor for easier routing and termination in switchboards and confined spaces.
• Low smoke, halogen free, UV stabilised: Our 110 degree SDI is suited to public buildings and occupied spaces where fire and smoke performance matters.
• XLPE insulation, PVC sheath: XLPE's thermoset structure gives the core insulation strong thermal and electrical performance, protected by a tough PVC outer sheath which is also UV stabilised.
• Built for switchboards and mains work: Sized and rated for mains, submains, and subcircuit applications in buildings and industrial plant.

Flexible single core cable uses a stranded, flexible copper conductor insulated with cross-linked polyethylene (XLPE). Being a thermoset material, XLPE offers strong dielectric and thermal performance without softening under load, and is protected by a PVC outer sheath. Compared with a rigid single-core cable, the finer stranding of the flexible range makes it easier to route, bend, and terminate within switchboards and confined enclosures. The low-smoke, halogen-free variant substitutes a flame-retardant, halogen-free compound to reduce toxic smoke and corrosive gas release in a fire.

Flexible single core cable is the standard choice for mains switchboard wiring, submains, and subcircuits in commercial and industrial buildings. Its single-core construction and flexibility make it well suited to switchboard and panel work where individual conductors need to be routed and terminated cleanly. The low-smoke, halogen-free variant is specified for public buildings and other occupied spaces where flame-resistant performance is a priority.

• What does SDI stand for? SDI stands for single-double-insulated; a single-core cable with two layers of insulation, giving it both electrical and mechanical protection.
• What's the difference between the 90°C and 110°C ranges? Both use the same flexible XLPE/PVC construction, but the 110°C Flexible SDI range is rated for higher continuous operating temperatures and current-carrying capacity than the 90°C Flexible XLPE range.
• Is flexible single core cable suitable for public buildings? Yes. A low-smoke, halogen-free version is available, reducing toxic smoke and corrosive gas release in a fire — a common requirement for cabling in public and occupied buildings.