Radial Circuit
Sockets fed in a single line from the CU.
● Line● Neutral● Earth
Tap any wire, switch or device to see what it is.
Useful Information
Simple, easy to test and fault-find. Common for new kitchens, extensions and dedicated appliances.
Important to know
- 20 A: 2.5 mm², up to 50 m². 32 A: 4 mm², up to 75 m² (Appendix 15).
- Check voltage drop (5% power, Appendix 4) on long runs.
- 30 mA RCD for sockets ≤32 A (411.3.3).
BS 7671:2018+A4:2026 references
411.3.3433.1525Appendix 15
Study notes paraphrased — check against your copy of BS 7671.