A safety note for all about the dangers of a shared/borrowed neutral.
In this case, whether you were to test with a neon screwdriver or a multimeter, the shared/borrowed neutral would not show up by simply testing for voltage until the two neutral conductors had been split at the socket.
All the time there is continuity between the two conductors, both would be held at or near 0 Volts by the neutral connection at the CU.
As soon as they are seperated, then the conductor with the shared neutral would show 240 Volts present on the neutral.
In this case, whether you were to test with a neon screwdriver or a multimeter, the shared/borrowed neutral would not show up by simply testing for voltage until the two neutral conductors had been split at the socket.
All the time there is continuity between the two conductors, both would be held at or near 0 Volts by the neutral connection at the CU.
As soon as they are seperated, then the conductor with the shared neutral would show 240 Volts present on the neutral.
