110V, 115V, 120V, 125V, 220V, 250V confusion
 

120 plus or minus 5%.

There are many stories about where the other values come from; I haven't
heard one that sounds credible.

Again, I'm hungover and tired - but ius it possible they are a
spillover from multi phase vs single phase?
http://www.faqs.org/faqs/electrical-...ection-10.html

120 plus or minus 5%.

There are many stories about where the other values come from; I haven't
heard one that sounds credible.

http://nonstop.compaq.com/TechPubs/P...nts/TPAPPA.pdf

In the USofA, You can always get three-wire service, with 2 feeds
that are nominally 120V to ground, and 240V from each other, at 60
Hertz.
The voltage tolerances vary by jurisdiction from 2-8% of the nominal
voltages. In many places, you can also get 4-wire residential service,
still with 120V on each hot to ground, but with each of the three lines
at 208V from each other.


Most of Eurasia appears to use 2-wire service with 220V to ground,
or variations thereof.



--Goedjn

On Fri, 07 Jan 2005 18:42:25 GMT, "toller" wrote:

120 plus or minus 5%.

There are many stories about where the other values come from; I haven't
heard one that sounds credible.


A lot of residential outlets will measure 125 V. The trend over the
years has been to higher voltages as it is more efficient.

110 Volts originated with the original Edison systems where the
voltage supplied was 110 VDC. The reason he picked this voltage was
a compromise between safety and efficiency and the ability to match a
suitable incandescent lamp filament with a useful life expentancy and
a suitable output level in lumens. Minimizing excessive voltage drop
and the cost of expensive copper conductors was also a consideration.

When AC replaced DC, the 110 voltage stayed the same. In the 1950's
this increased to 120 volts. Many devices were still rating stamped
110v. 115v. or 120v.

Beachcomber

toller wrote:

120 plus or minus 5%.

There are many stories about where the other values come from; I haven't
heard one that sounds credible.

FWIW, here's a pointer to an "INTERIM OPINION ON EMERGENCY VOLTAGE
REDUCTION MEASURE" that
was up before the California state PUC with regards to lowering the
nominal line voltage to
117VAC during times of electrical energy shortage.

http://www.utilityregulation.com/con.../02CA13831.pdf

Makes sense that with a lower voltage the demand for power decreases.
However, this only
follows for resistive devices. Constant power loads (like motor-driven
equipment) would demand
greater current and cause increased conductor loss as well as increasing
risk of failure to
the equipment.

Dunno if they ever implemented this; at my house the voltage gyrates
quite a bit throughout the
day anyway so it's hard to tell what the "nominal" is.

later,
L

Beachcomber wrote:
On Fri, 07 Jan 2005 18:42:25 GMT, "toller" wrote:

120 plus or minus 5%.

There are many stories about where the other values come from; I
haven't heard one that sounds credible.


A lot of residential outlets will measure 125 V. The trend over the
years has been to higher voltages as it is more efficient.

110 Volts originated with the original Edison systems where the
voltage supplied was 110 VDC. The reason he picked this voltage was
a compromise between safety and efficiency and the ability to match a
suitable incandescent lamp filament with a useful life expentancy and
a suitable output level in lumens. Minimizing excessive voltage drop
and the cost of expensive copper conductors was also a consideration.

When AC replaced DC, the 110 voltage stayed the same. In the 1950's
this increased to 120 volts. Many devices were still rating stamped
110v. 115v. or 120v.

Beachcomber

You know I remember it being 110V, but I could not remember when it
changed or why. Thanks for the history. I was there in the 50's and just
old enough to know it was 110V.

--
Joseph Meehan

26 + 6 = 1 It's Irish Math

FWIW, here's a pointer to an "INTERIM OPINION ON EMERGENCY VOLTAGE
REDUCTION MEASURE" that
was up before the California state PUC with regards to lowering the
nominal line voltage to
117VAC during times of electrical energy shortage.

http://www.utilityregulation.com/con.../02CA13831.pdf

Makes sense that with a lower voltage the demand for power decreases.
However, this only
follows for resistive devices. Constant power loads (like motor-driven
equipment) would demand
greater current and cause increased conductor loss as well as increasing
risk of failure to
the equipment.

Dunno if they ever implemented this; at my house the voltage gyrates
quite a bit throughout the
day anyway so it's hard to tell what the "nominal" is.

later,
L

One solution if there is not enough power to go around is to lower the
line voltage. This is called a brownout.

Another solution is to have rotating blackouts as California did a few
years ago.

Remember that this is only for California where most electrical
consumers are at the far end of the (transmission) line. They pretty
much don't like large conventional power plants in California (be they
nukes, coal-fire, hydro-electric dams, or gas fired units) and are not
building a whole lot more.

Because of this, a lot of California power comes from outside the
state (Oregon, Washington, British Columbia) in the north and Hoover
Dam and other sources (Nevada - Arizona) in the south. There is
only one Nuke in the state and quite a few medium and smaller sized
hydro-electric dams in the mountains. Geothermal also makes a small
contribution.

Beachcomber

Beachcomber wrote:

snip


Remember that this is only for California where most electrical
consumers are at the far end of the (transmission) line. They pretty
much don't like large conventional power plants in California (be they
nukes, coal-fire, hydro-electric dams, or gas fired units) and are not
building a whole lot more.



Well, they don't like building them close to the populated areas. But
there are quite a few ancient plants in the populated areas of So Cal.
Look for those tall stacks at the beaches and such.

Because of this, a lot of California power comes from outside the
state (Oregon, Washington, British Columbia) in the north and Hoover
Dam and other sources (Nevada - Arizona) in the south.

Known as the Pacific Intertie. Palo-Verde Nuclear in Arizona. Four
Corners coal fired in New Mexico. Don't know of much coming out of
Nevada, Las Vegas sucks up enough power!

There is
only one Nuke in the state

Two that come to mind right away. San Onofre for SCE and Diablo Canyon
for PG&E

and quite a few medium and smaller sized
hydro-electric dams in the mountains.


Big Creek is a decent size project but as with any hydro, it doesn't run
year round. Especially during droughts!

Geothermal also makes a small
contribution.



As does wind,

Beachcomber

Mark and Kim Smith wrote:

Beachcomber wrote:

snip
....
There is
only one Nuke in the state

Two that come to mind right away. San Onofre for SCE and Diablo Canyon
for PG&E
....

And 850 MWe of perfectly good idled capacity at Rancho Seco...

"Joseph Meehan" wrote in message
...

You know I remember it being 110V, but I could not remember when it
changed or why. Thanks for the history. I was there in the 50's and just
old enough to know it was 110V.

--
Joseph Meehan

I remember the 50s and one of those lessons a little kid learns - from my
recollection, the 110 felt about like 120 did later in life when I should
have known better!

"Sparky"