hi whilst testing ELI on lighting circuits, using kewtech kt63 on loop no trip function, test keeps tripping rcd once polarity and voltage is confirmed. I know the kt63 tests at 250v in this mode, but it shouldn’t trip the rcd, anyone else experienced this? Is it calibration time? Is it me? Is it the rcd? Anyone’s thoughts, and I know the calculation is Zs =(Ze + r1r2), a bit frustrated the damn things keep tripping, upstairs and downstairs, separate circuits, separate rcds, both trip.