Shower circuit design.

That picture you posted Andy is nonsense, the failure was caused by a loose connection! Just who or what are you trying to fool? I do not understand why everyone is trying to prove that there is something in the regulations which doesn't cater for circuit overload. Perhaps you do not understand how MCBs work? It is surely obvious to you that the normal operation of the thermal element must be designed to not cause danger or failure? A product that failed could not pass the approval tests and would be unsaleable. 

You are now suggesting that MCBs need to be spaced to prevent overheating. Whilst that might be true at very high ambient temperatures in particularly demanding circumstances, why do you think such spacing is NOT designed into CUs or any other circuit protection system? In a domestic CU, the average consumption is very small. How long do you think it would take to make the whole box at an excessive temperature, given the very small overall dissipation of the very few MCBs?

That picture you posted Andy is nonsense, the failure was caused by a loose connection! Just who or what are you trying to fool? I do not understand why everyone is trying to prove that there is something in the regulations which doesn't cater for circuit overload. Perhaps you do not understand how MCBs work? It is surely obvious to you that the normal operation of the thermal element must be designed to not cause danger or failure? A product that failed could not pass the approval tests and would be unsaleable. 

You are now suggesting that MCBs need to be spaced to prevent overheating. Whilst that might be true at very high ambient temperatures in particularly demanding circumstances, why do you think such spacing is NOT designed into CUs or any other circuit protection system? In a domestic CU, the average consumption is very small. How long do you think it would take to make the whole box at an excessive temperature, given the very small overall dissipation of the very few MCBs?