I fitted some A/C's the other day and did the Testing on them. I ran them through a type C RCBO 20A and when measuring them came across a rather higher value on the furtherest one. The runs are aproximately 17.5m and 13.5m, run in seperate radials and off 6mm T&E.
I wasn't expecting the Zs to be that much higher than the closer A/C as it only exceeds it by about 5m.
I remember something about high Zs values and if exceeded then an RCD must be applied. Can someone confirm this?
What would be the other causes of a high Zs value?
Information is always appreciated.