I've just had an electrician around who says my lazer printer may be
surging in its power usage which trips the overload protector switches
(what used to be fuses).

If this is the case, I will find out, but I have a problem with
printing now - what do I do to protect the mains ring from tripping if
the printer does indeed overload it? The electrician says the fuses
on the box are pretty standard (40 watt limit I think he said).

The electrician says he has encountered this before. So the printer
overloading is probably the problem (I suppose they use a lot of
watts).