Student training aid for continuity of a ring final circuit and polarity. Using a MFT Megger tester set to the ohms scale. This video follows the 3 stage required to prove a ring final circuit is wired correctly. The circuit is wired in 2.5mm2 twin and cpc cable (twin and earth) as it is in a domestic installation.
Things of note: finding r1, rn, r2, R1 + Rn, R1 + R2, 1.67 ohms and proving one of the sockets is a spur from the ring.
Videos are training aids for City and Guilds (C and G) and EAL courses Level 1, 2 and 3.