Newsgroups: sci.engr.electrical.compliance
Subject: Re: pratiti's quiary- why do some countrie's have 110v supply (freq?) and some 220v-50hz
References: <[email protected]>
[email protected] (Pratiti Biswas) writes:

> pratiti's quiary- why do some countrie's have 110v supply (freq?) and
> some 220v-50hz. what is the advantage or disadvantage of them?

The mains voltage is a selection between cost, efficiency and
safety. Higher voltage means that you need less current to carry
same power -> you have less losses on wiring and need thinner
wires to carry same power -> less costs.
Higher voltage is more dangeroust to touch.

In ancient histiry there used to be larger variation
of voltages and even DC power feed. Things get standardized
over the time and USA adopted 110V 60Hz (safer than 220V)
as the normal mains power in normal household.
There are also other voltages available for heavy special
(usually permanently wired) devices like air conditioners
etc. (usually 220V for those).

European countries though that 220V was not too dangerous
if connectors and electronics devices are construted in the
safe way (so that is pretty impossible to get in touch with that).
Wiring with 220V is cheaper to do, beause wire do not have
to be that thick and you get easily more power from
mains outlets. An dyou do not need ansy pecial outlets
for specially high loads..


-- 
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at 
http://www.epanorama.net/