Inspection & Testing

Checking continuity of a ring final circuit


This diagram provides guidance for checking the continuity of ring final circuit conductors for compliance with Regulation 612.2.2.

This should be viewed as step two to the post: Checking the continuity of live and protective conductors.

  1. Ensure installation, or appropriate part of it, is securely isolated, and proved to be so, before proceeding.
  2. Cross-connect the incoming neutral conductor with the outgoing phase of the circuit, and vice versa.
  3. Measure the resistance phase to neutral and note the result which should be approximately half the measured value of the phase or neutral conductor measured separately (as in Step 1).
  4. Alternatively, the measured value at each socket-outlet should be substantially the same. This measurement would be (r1+rn) or (1 + rn)/4.

The next diagram from Megger shows how you can check the continuity of ring final circuits with no spur.