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Ring Final Circuit Test
Three-step test to prove ring continuity.
Step 1
Measure end-to-end r1 (line), rn (neutral) and r2 (cpc). r1 and rn should be within 0.05 Ω. For 2.5/1.5 T&E, r2 ≈ 1.67 × r1.
Step 2
Cross-connect L and N; readings at each socket should be ≈ (r1 + rn)/4.
Step 3
Cross-connect L and cpc; readings at each socket ≈ (r1 + r2)/4 — the highest value is R1+R2 for the circuit.
Key regulations
643.2.1