The "polarized" plug is for extra user safety. AC outlets have
polarity-specific sockets because some devices can easily become dangerous
if the polarized device is plugged in backwards. This happens when the
switch or fuse inside the appliance is designed to disconnect only the "hot"
and not the "neutral" wire when the device is switched off because it is
cheaper than switches that disconnect both wires. The "neutral" wire is
typically connected to ground at the main panel, so it is safer to use the
switch to open the "hot" wire.

The device could still be "hot" even when the switch is off. Without a
polarized plug, you can't tell which wire the switch will disconnect and may
receive a shocking surprise!

In theory, safe devices are designed to keep a user from touching either the
hot or the neutral. designers know which wires will be "hot" inside the
device, they can take extra precautions to make sure they cannot break apart
and electrify anything a user can touch. A broken "hot" wire can electrocute
a user. Therefore, many appliances now have a polarized plug so the switch
always disconnects the "hot" side.

A so-called "double-insulated" (IEC Class II) device may have a
non-polarized plug because the same safe design has been made for BOTH
conductors No single internal fault would be likely to cause an
electrocution hazard.

Furthermore, even with a polarized plug, a single internal fault can be
deadly in an ordinary appliance. The third prong (ground) can save your life
if there is an internal fault of the hot touching exposed metal, and a GFCI
can save your life if there is an internal fault of the neutral to exposed
metal (where you could otherwise become the missing "neutral" connection to
ground as you are electrocuted).

You are an ignorant fool to grind down the polarized plug.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
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"marlboroman" wrote in message
...
Has anyone ever figured out why they put one wide and one narrow on a
plug that does not have a ground?

OK, I understand that on a lamp it's a good idea, or the socket shell
and bulb threads will be live if the hot side of the power line is
connected to that part of the socket.

But, lets say I have a all plastic cased electric power tool. (Like
all of them made in the last decade or more). I'm holding plastic,
which does not conduct electricity. It dont matter which side of the
power line goes to which side of the motor on AC. What's the point of
having that wide terminal? Is the only reason to **** off the user,
particularly those of us who are older and dont have the best eyesight
anymore. I cant see any other reason.....

My grinder does a quick job of narrowing that wide prong though !!!
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