lol well isolation by the lighting mcb is hardly isolating with out affecting the operation of the lighting circuit is it? or do u guys use emergency fittings throughout domestic installations so wen the lights go out the batteries take over? Definition of isolation .... A function intended to cut off for reasons of safety the supply from all or a discrete section, of the installation by seperating the installation or section from every source of electrical energy (ie breaking live and neutral conductors). So unplugging a detector from its base is not seperation from every source of electrical energy, as the base which may need changed if using a different make of detector is still live. Im not saying anyone is wrong i just believe my way is the best way, on a further note if they want to turn the smokes off they will simply take them down, just because they are wired into the lighting mcb will not deter them, my keyswitch is clearly labelled smoke alarms do not turn off! if they choose to ignore that advice then thats up to them there is just no helping some people.
