>You do not want to ground to the electrical system. Ground
>yourself only to the computer case. That way you are always
>at the same potential as the circuit board whether its
>plugged in or not.
>
>There is no need to be continuously in contact with ground.
>Just touch it before you start working and again if you walk
>away and return. A static charge must be generated, just
>standing or sitting there working will not generate any
>significant charge. It takes several thousand volts of
>static charge to do any damage, and those levels are not
>easy to accumulate. In very low humidity conditions, avoid
>wearing nylon clothing, it is an excellent static generator.
>
>This whole business about static damage is highly overblown.
> I don't even own a wrist strap, never have. Just take
>sensible precautions and you will neve have a problem.

Oh wow, I always just wired my wrist strap to the 13 amp house socket (ring main) earth & trusted that this was sufficient, thankfully I always touch the cae anyway, looks like I need to rewire my strap to a croc clip!

Thanks for that info! ie: common earth = the CASE not the mains.