06-11-2012, 05:58 AM
I should also explain that an isolated power supply (one with no connection to earth) is a good thing. If you were to accidentally touch a live wire from the generator, you actually wouldn't get a shock due to this "isolation". There is no circuit formed through your body (to earth). Like a bird landing on an overhead power wire.
If you earth the generator with a stake, a potential circuit will now exist so that if you touch that same live wire as above, your body now forms a circuit (back to the earth stake through the ground) and you get electrocuted - unless a protective device is there to save you (eg. RCD).
Isolated power supplies are completely impractical for wider energy distribution systems so they don't exist other than portable generators and special circuits (connected through isolation transformers).
If you earth the generator with a stake, a potential circuit will now exist so that if you touch that same live wire as above, your body now forms a circuit (back to the earth stake through the ground) and you get electrocuted - unless a protective device is there to save you (eg. RCD).
Isolated power supplies are completely impractical for wider energy distribution systems so they don't exist other than portable generators and special circuits (connected through isolation transformers).