Man-wai Chang said:
My mistake calling that pin the GROUND pin resulting in a bit of
confusion.. It should be called EARTH.
We have the same scheme here. Three prongs on the plug. The
third prong is a safety ground connected to earth. My current
house has the three pronged outlets. (Not all of our plugs
are this ugly
Many are molded and nicer looking.)
http://www.mcmelectronics.com/content/productimages/s4/4012023.jpg
Not all homes here, have three prong outlets. The home I was
born in, only has two prong outlets. This presents a problem
with things like computers. If you were to use a computer with
a three prong plug in that house, you'd get a mild shock every
time you touched the metal of the computer chassis, as well
as touching any other object in the vicinity that is at earth
potential. That is because there is no way to connect the
safety prong of the computer, to earth.
My grandmother's home, by comparison, was so old, the wiring
consisted of two separate wires, suspended on porcelain insulators
at regular intervals. (I presume that was in the walls, as well as
exposed in the basement.) As a kid, I think I was in the basement
once, and saw something similar to the concept pictured here. (The
basement was so dirty, it's not a place I would stay for long. It
was like a dungeon down there.) These aren't the exact insulators,
but they're similar in concept. This home didn't have any heavy
electrical loads in it, no central heating or central air conditioning.
It was heated with stove oil (bottled oil, heater in hallway), and
cooking was on a wood stove. The heaviest load was probably when
using an electric kettle (in later years). I think my grandmother's
house has been demolished, so is no longer a safety issue for anyone
http://images.oldhouseweb.com/stories/bitmaps/10327/knob-and-tube-2.jpg
There is no need in our country, to upgrade the wiring, as an old
installation of decrepit nature, is "grandfathered" and allowed
to continue to exist. Due to the amount of damage to walls and the
like, necessary to change it.
My current home, is the one on the right. The one on the left, is
similar to the house I was born in. In the one on the left,
a desktop computer would give you a shock, from leakage current
that has no place to go. To plug a three pronged computer into
a two pronged outlet, you buy a "cheater" adapter which has
the safety prong missing. The second picture shows a "cheater"
in usage, and why the safety earth ends up "floating".
http://s3.amazonaws.com/atimg/1127383/home-hack-three-prong-outlet_rect540.jpg
http://www.vincehuston.org/images/adapter_3_prong_vlh.gif
Paul
