Ring Final Circuit Calculator

Calculate expected ring continuity values and verify measured readings per BS 7671

Ring Circuit Details

Enter the ring final circuit parameters

Cable Size

Total Ring Length*

Full ring length (out and back)

Protection Type

Protection Rating

Ze Value (Optional)

For Zs calculation

External Loop Impedance (Ze)

Typically 0.35Ω for TN-C-S, 0.8Ω for TN-S

Measured Values (Optional)

Enter measured values to verify against expected

Measured R1 (Line)

Line conductor end-to-end

Measured Rn (Neutral)

Neutral conductor end-to-end

Measured R2 (CPC)

CPC end-to-end