What safety regulations to I need to adhere to when installing an 8.5km electric shower?

Question:i.e. thickness of cable between 'pull-chord' box and shower, thickness of cable between 'pull-chord' box and fuse box, do I need an RCD / RCBO in the circuit, if not, should the shower be on its own circuit and what size of fuse would be required?

Answers:
8.5kw = 8500watt divided that by 230volt gives u 36.95amp

You will need a 10mm Twin and earth cable on its own circuit protected by a Type B 45amp RCBO/MCB (RCBO provides both overcurrent and earth leakage protectection) but this depends on wether u have a split load fuse board (IE Half of it is protected by a normal main isolater the other half by an RCD. If u dont have one use a RCBO which is at 42amp and rated to 30milliamp. All of the cable run needs to be in 10mm T&E and the pullcord needs to be rated to at least 42amp