I have just watched a video where a guy uses contactors in the DB as isolators ...they run a trigger wire from a switch panel in the kitchen which switches the contactor on and off.

Where i would think this is a brilliant idea ...fast food stores... if you have ever worked in a fast food store ...you will notice all the plugs or isloators above the cooker units ( i dont know how they pass it like that considering the 3 phase sockets are not connected to 3 phase earth leakage) just imagine trying to switch off the plug or isolator if there is a fire.

This would also work for washing machines...tumble driers etc where the outlet is normally behind the unit... you have the trigger for the contactor in a switch panel in an accessible position ...not in a cupboard above the fridge.