turning off the mains switches - necessary??

Sorry if anyone was having trouble with that film clip; the Geocities site I had it on seems to be having some problems.

I've moved the file onto a different server that I administer and changed the link above, so if you couldn't get it before, please try again now.   

Thanks for replying, Paul. The explanations you give are always so informative and interesting to read.

My pleasure.   

By the way, the integral switches on British sockets are a convention, but are not required by any sort of electrical code.   If you wanted to replace your sockets with unswitched types that would be perfectly acceptable, although the majority of people would probably find it a little unusual.   Unswitched sockets tend to be used mostly in semi-inaccessible places which are used for specific things, such as a disposal outlet, washer outlet behind a cabinet, etc.