The common voltage in Canada was always 120/240v. I believe the USA was the
same except that the USanians have their own measurement system for almost
everything else so who knows about what they nay have done.

Equipment was rated at 100v, 115v, 117v and 120 v over the years. This was
mostly just due to ignorance and foreign ignorance. The same thing happened
with 240v. It was labelled 220v, 230v and 240v. Some equipment is still
labelled at 250v which is only a class of equipment distinction. (max
capability).

This all applies to single phase descriptions. Some of the confusion can
attributed to 3 phase systems were 208v, 220v and 240v have been used and
bleeds over into single phase systems.

600v, 3 phase systems went through the same thing with 559v, 575v and 600v
being used. The US and western Canada use 480V systems and I am sure went
through the same crap of 440v etc..

The network style voltage or as some called it "3 phase 4 wire one leg out"
is used in apartment and multi dwelling complexes. They have 3 phase 4 wire
transformation and run two out of three phases (with shared neutral) to each
apartment floor or unit. This would give them 120/208v circuits. The 208v is
quite low for the 240v baseboard and appliances so they compromise both
voltages and came up with 125v/216v (root 3 factor). The 125 v is a little
high but within specs (+/-10%) and the 216v is a little but within the specs
also. Tougher lamps are in order to survive on this system. The end result
is much less copper to feed a huge complex.

The end result is there are many terms falsely used but mostly compatible.

I hope some of this helps.

"Ulysses" wrote in message
...

"Me" wrote in message
...
In article ,
"Ulysses" wrote:

"wmbjk" wrote in message
...
On Thu, 16 Jun 2005 15:43:10 GMT, "Pete C."
wrote:



Not necessarily. Home welding tends to be short duration. The
hardware
to supply that kind of power is actually affordable, and if one is
designing the power system from scratch for what most would consider
a
normal home, then the extra inverter capacity isn't a big deal. In
our
case, for the house loads alone we could have gotten away with a
single SW4024 plus a transformer for the 220V loads.

How is this done, getting 220V from 110? How do you get the two "hot"
wires? Are there 2 secondary windings on the transformer? Wouldn't
they
need to be out of phase with each other?



Now here is a fellow that asks an inteligent question. If you take
a dual winding secondary with 120 Vac on each winding, feeding it
with a 120 Vac Primary, and connect the dual 120Vac windings in series
you get 240Vac. The phase is determined on how you connect the two
series windings. and they will either be inphase or 180 out of phase,
depending on the connection.

Me

Something else I've wondered about is why is it sometimes called 220,
other
times 230, and also 240VAC? Do the different voltages imply single or
double phase or is it just a matter of different voltages in different
geographic locations? My little Honda generator is rated at 125 VAC which
seems to be unusual and that would give us 250 VAC if it was ran through
the
step-up transformer.