[ltp] Electric shock from t40 in France

[Pekka Pessi]

Steve Krulewitz <shooz@mm.st> writes:
>Excuse my lack of knowledge about electricity :)  The plug on my IBM adapter
>is 2 prong, so it is not making any contact with the ground pin. If this is
>the case, could it still be a grounding problem?  Are you suggesting the
>wiring in the place I'm staying is messed up and it will not happen
>elsewhere?

There is no problem with the wiring. 

I have two Thinkpad power supplies with two-wire cord that were
shipped with my first X20. They were originally intended for
Japanese market, I think. When using them I can feel the tingle
when touching the case on the spots where there is no insulating
coating.

Unless you have ground wire connected to your your power supply,
the output of your power supply is "floating" between the two
power lines. The voltage that you felt is roughly half of the wall
voltage, about 115 V in France, 55 V in America. While the voltage
may sound large, the current getting through is so small that
there is no danger.

If the tingling annoys you, you can get an European cord with
grounding plug for a few Euros (provided that you have a power
supply with a three-wire cord in first place). The same cord can
be used in most of the continental Europe. In France the grounded
sockets have a ground finger sticking out of them.

I don't use plug adaptors with my Thinkpad anymore (partly because
of tingling, partly because forgetting large number of adapters in
sockets all around North America), but I have spare cords with US
plugs with me when travelling.

--Pekka