Schemes

Ring Final Circuit

32 A ring in 2.5/1.5 mm² T&E serving up to 100 m² floor area (Appendix 15).

32 A
● Line● Neutral● Earth

Tap any wire, switch or device to see what it is.

Broken ring

Useful Information

Both ends of the ring connect to the same device, so current shares two paths.

Toggle 'Broken ring' to see a break — the circuit still works, which is why the ring test matters.

Important to know

  • Number of unfused spurs must not exceed the number of sockets on the ring (Appendix 15).
  • Kitchens with heavy loads may need a separate circuit.
  • All sockets ≤32 A need 30 mA RCD (411.3.3).

Testing tips

  • Step 1: end-to-end r1, rn, r2. r1 and rn should be within 0.05 Ω.
  • Step 2: cross L–N, readings at each socket ≈ (r1+rn)/4.
  • Step 3: cross L–E, readings ≈ (r1+r2)/4 — highest is R1+R2.

BS 7671:2018+A4:2026 references

411.3.3433.1.204Appendix 15643.2.1

Study notes paraphrased — check against your copy of BS 7671.