Table of contents
Introduction
Installers often ask: Which SWA Core Cable Do I Need? The answer depends on load, protective devices, and the environment under BS 7671 Wiring Regulations – IET. Choosing the correct core ensures safety, efficiency, and compliance.
Core Selection (General Guidance)
Selecting the right core count is a key part of circuit design:
- 2-Core SWA – sometimes used for single-phase where CPC is not required.
- 3-Core SWA – the most common for single-phase, providing line, neutral, and CPC.
- 4-Core SWA – typically used for three-phase without neutral, or for control circuits.
- 5-Core SWA – standard for three-phase with neutral, or advanced control wiring.
- 7-Core and higher – mainly for specialist control or signalling applications.
Core Selection: PVC SWA Options
For standard installations, our PVC armoured cable categories include:
- 3-Core PVC SWA Cable – standard single-phase supply with CPC.
- 4-Core PVC SWA Cable – control wiring or three-phase without neutral.
- 5-Core PVC SWA Cable – three-phase with neutral or advanced control wiring.
PVC or LSZH: Two Sheath Options
Modern Armoured Cable Range is available in just two sheath types:
- PVC SWA – standard choice for outdoor, industrial, and domestic installations where fire performance is not specified.
- LSZH (or LSNH) SWA – required in public buildings, tunnels, transport hubs, or enclosed spaces where reduced smoke and halogen-free performance is critical.
Note: Doncaster Cables datasheets use LSNH (Low Smoke Non-Halogen), which is the same as LSZH (Low Smoke Zero Halogen).
LSZH Options by Core Size
Where smoke and halogen-free properties are required, choose:
- 2-Core LSZH SWA
- 3-Core LSZH SWA
- 4-Core LSZH SWA
- 5-Core LSZH SWA
- 7-Core LSZH SWA – specialist control applications.
Buying Tips – Which SWA Core Cable Do I Need
Explore the Armoured Cable Range to compare all sizes and sheath types. For small jobs, order SWA By The Metre. Complete installations neatly with SWA Glands And Banjos and secure routes using SWA Cable Clips.
FAQs – Which SWA Core Cable Do I Need
Which SWA core is most common in domestic installs?
3-Core SWA is most often used for single-phase circuits, providing line, neutral, and CPC.
When do I need 5-Core SWA?
5-Core SWA is required for three-phase with neutral or for specialist control applications.
Why would I choose LSZH instead of PVC?
LSZH (LSNH) reduces smoke and toxic gases in a fire, making it mandatory in many public or enclosed buildings.
Can I mix core counts in the same project?
Yes, provided each circuit is correctly designed, protected, and terminated under BS 7671.
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Choosing Between 2‑Core, 3‑Core, 4‑Core and 5‑Core SWA Cables