OK here goes. I have a split consumer unit that is wired normally. One of the MCBs on the non protected side (I have checked that the neutral is on the non protected neutral block) trips the RCCB when ever the MCB is reset. The MCB does not trip itself, it just trips the RCCB! So I am unable to have the MCB (remember its on the unprotected side!) and the RCCB set at the same time. The MCB is question is on the non protected side so how can it be tripping the RCCB? Do I have an earth leak on that MCB? Any other help would be much appreciated. Thanks.