Twin and Earth Cable

• 1.0mm² 6242Y: Lighting circuits up to 6A
• 1.5mm² 6242Y: Lighting circuits up to 10A
• 2.5mm² 6242Y: 32A socket ring final circuits, 20A radial circuits
• 4.0mm² 6242Y: Longer radial circuits, 32A radial sockets, immersion heaters
• 6.0mm² 6242Y: 40A or 45A cooker circuits, 40A shower circuits
• 10.0mm² 6242Y: 50A shower circuits, sub-mains to outbuildings
• 16.0mm² 6242Y: Heavy sub-mains, larger shower or cooker installations

Use our cable calculator to confirm the correct size for your circuit

Twin and earth cable is the standard fixed wiring cable for UK domestic and light commercial installations. Typical applications include:

• Lighting circuits - usually 1mm² or 1.5mm²
• Socket ring final circuits - 2.5mm² protected by a 32A MCB
• Radial socket circuits - 2.5mm² or 4mm² depending on length and load
• Cooker and shower circuits - 6mm² or 10mm² depending on rating
• Submain runs to outbuildings, garages, annexes - 6mm² to 16mm²

Twin and earth cable must be installed in accordance with BS7671. It is suitable for clipping direct, installing under floorboards, in conduit, or in trunking.

Twin and earth cable is not a universal fixed wiring cable. It is not suitable for:

• Direct burial in ground - use SWA armoured cable instead
• External use without mechanical protection - PVC sheathed twin and earth is not UV resistant
• Continuously hot locations above 70°C - PVC insulation thermal rating limit
• Industrial control wiring - use SY/CY/YY control cable instead
• Public buildings where smoke and toxic fumes are a safety concern - use 6491B LSZH equivalent

Critical Risk: Using twin and earth in unsuitable environments can lead to insulation breakdown, fire risk, or non-compliance with BS7671.

Yes, twin and earth cable can be buried in plaster - subject to BS7671 safe zone or 30mA RCD protection requirements.

BS7671 requires cables buried in walls to be either:

1. Installed in safe zones (within 150mm of the top of a wall, or in vertical or horizontal lines from accessories), or
2. Protected by an additional 30mA RCD if installed outside safe zones, or
3. Mechanically protected by earthed metallic capping or armoured cable.

Modern UK installations almost universally rely on 30mA RCD protection at the consumer unit, which means twin and earth can be buried in any wall location subject to the RCD being in place.

The bare circuit protective conductor (CPC) in twin and earth cable must be sleeved with green and yellow sleeving at every termination point.

BS7671 requires the CPC to be clearly identified at every accessory and consumer unit termination. The bare copper conductor is sleeved with PVC green and yellow sleeving as it exits the cable sheath and runs to its terminal. Failure to sleeve the CPC is a common Code 2 issue on Electrical Installation Condition Reports (EICRs).

The 6242Y code identifies a specific cable construction under British Standards. "6242" denotes two insulated cores plus one bare circuit protective conductor, and "Y" denotes PVC as the insulation and sheath material. The cable is manufactured to BS6004 and rated 300/500V.

A UK 32A ring final socket circuit requires 2.5mm² twin and earth cable protected by a 32A MCB. 1.5mm² is not suitable for socket ring mains and is used for lighting circuits.

Yes, twin and earth cable can be buried in plaster. BS7671 requires the cable to be installed in safe zones (within 150mm of the top of a wall, or in vertical or horizontal lines from accessories) or protected by 30mA RCD if installed outside safe zones.

Yes. We cut twin and earth cable to the exact length you need on our automatic winding and measuring machine at Wrexham. You order the length you need, we cut it from the drum, and despatch reduces waste compared with buying a full 100m reel.

No, not without additional protection. PVC sheathed twin and earth cable is not UV resistant or suitable for direct burial. For outdoor or buried runs use SWA armoured cable instead - see our SWA cable range.