W
WilcoxElec
I need to rectify a fault where an outside SPA hot tub is supplied through a length of 3 or 4 meters of buried armoured (shielded) cable and – when the MCB is closed – after 10 seconds the 30mA type A RCD above this MCB opens – and so does another in parallel with this on a separate UK style CU. It is a TT schema installation here in France. I was wondering that I might have some sort of earth capacitance problem, rather than a straight leak to earth – ( because both RCDs flicking off – after the same pause). Could it possibly be caused through the sheathing on the armoured cable being connected to the earth? 
