Flat Twin + Earth 4mm² 3-Core Cable 10m

Choosing the Right Twin & Earth Cable Size

Twin & Earth cable is one of the most widely used wiring options in South African homes and small commercial installations. The correct cable size is critical for safety, performance, and compliance with SANS 10142 wiring regulations. Below is a simple guide to the sizes you will typically need.

2.5 mm²
This is the go-to size for standard wall socket circuits. It is usually paired with a 20 A or 25 A breaker and is suitable for everyday appliances like TVs, kettles, and computers. Most household plug circuits are wired with 2.5 mm² Twin & Earth.

4 mm²
Used for heavier fixed appliances such as ovens, small geysers, or air-conditioning units, this cable size is generally protected by a 32 A breaker. It offers a safe margin for appliances with higher continuous loads.

6 mm²
This size is ideal for larger single-phase loads or short sub-feeds. It is often used for high-demand appliances such as point-of-use water heaters, small sub-distribution boards, or compact workshop machines. Breakers in the 40 A to 50 A range are typical for 6 mm² cable.

10 mm²
For the largest single-phase loads, including compact EV chargers or small sub-mains, 10 mm² cable is the preferred choice. It is robust enough to handle currents up to about 63 A (depending on installation conditions), ensuring safe power delivery to demanding equipment.

Other Points to Remember

• Always choose a cable size that matches the breaker rating and the load. The breaker protects the cable, not the appliance.

• Voltage drop, grouping of cables, and long cable runs can affect the required size. When in doubt, move up one size to maintain safety margins.

• Twin & Earth cable includes a smaller bare earth conductor (CPC), which is still sized to clear faults as required by the regulations.

• For domestic and light commercial work, 2.5 mm², 4 mm², 6 mm², and 10 mm² will cover nearly all common installations.