Originally Posted by dsk
Originally Posted by Texas_Ranger
......favoured isolated rooms in homes (in a room without earth potential even touching a live wire can't create a dangerous current flow). Isolated room systems typically use 2-pin outlets and class 0 or class 2 equipment. Class 1 is safe as well as class 1 without earth connection is just class 0.

These days it's nearly impossible to create a room without earth potential with metal air ducts, central heating pipes in case of hot water heat, antenna wire shields, network cable shields etc. etc.


This way of thinking was the rule her in Norway too, even with pretty good grounding trough steel tubes for central heating, grounded coax on the antenna systems etc. The rule was no grounding needed if it was at least 2 m (=yd) from a grounded surface to the outlet.

By experience I may tell touching a single live wire standing on a surface of a PVC floor are at least unpleasant :-)

But even older American buildings has 2 pin outlets.


Yup, even until the early 60s some buildings did not have grounding outlets. Our ranges and ovens had none grounding outlets until 1996, but simply used the neutral to ground. A bad idea, but that is how it worked.