rule of thumb. add the In values of thre MCBs and the x 0.4. on OP's figures thats around 30A. in actual fact that' figure itself is pessimistically high. rare i see > 10A on a clamp here at home. when it's > 10A, i tell 'er inddoors to switch buggers off.
Reading through that was just about exactly what I was going to say haha any way I can't see a problem adding a shower mate my house has 2 showers in as well as the standard stuff.
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