Hi all

Quick q for the leckies out there!
I have a split load cu with upstairs and downstairs rings covered by common
RCD.
If I turn off the downstairs ring at the breaker and check Live-earth and
Neutral-earth with a crude tester, I get no indication of voltage flow.
If I accidentally dab live or neutral to earth, then it knocks out the RCD.
So where is the current flow being generated which will trip the RCD when
the live is isolated at the breaker?

TIA

Phil