Boy, Nick... you sure are impressive. I'll bet you don't have a mirror in
your house that's good enough to display your perfect image. I'll bet you're
a real blast at parties, though.

I'm surprised you could take time away from your job at NASA to display your
great intelligence here.

Thank you not,

Jake

It's just amps. A coulomb is an amount of charge, eg a quantity of
electrons. Amps are coulombs per second. Amps per hour would be
"coulombs per second per hour," which makes less sense than
miles per hour per hour, in this context.

Nick

TURTLE wrote:

"Tony Hwang" wrote in message news:l5CDc.909871$oR5.99416@pd7tw3no...

wrote:


Jake wrote:



kWh is power in Thousands of Watts, expressed over time.


That might work, if "expressed over" means "multiplied by" :-)
But I don't like the first part ("kWh is power..."), since
kilowatt-hours (and Btus) are a measure of energy, not power.



Watts are expressed as Amps x Volts.(for single phase, but let's not
complicate it further).


watts = amps x volts x power factor. This can make a big difference.
Some undercounter fluorescent fixtures have a power factor of 0.4.



IE An air conditioner consuming 10 amps at 120 volts consumes 1,200 watts.


Only if the power factor is 1.0.



The term "Watts" defines "True Power", and Turtle's explanation is correct.

5 amps x 240 volts = 1,200 watts
10 amps x 120 volts = 1,200 watts.


Only if the power factor is 1.0.



...please don't ever, ever, ever use an extension cord without
talking to an electrician first.


Would you be an electrician, by chance? :-)

Nick


Hi,
Again Volt x Amp and Watt is two different thing. Watt rating is always
less than Volt x Amp.
This is such a basic thing in theory, Sigh!
Tony



This is Turtle.

Tony You lost the Battle here with your theory. Theory only is good in Estimates and not in Readings from the Equipment it is really
drawing. If a Motor has a Name Tag estimated Amp draw of 5 amps per hour at 120 volts or it has a estimate of 600 watts per hour
rating. You can use the estimates but they will never be that high but will be less but will be exactly in direct proportion of the
estimate amp or watt draw of the motor.

Volt X Amps = Watts will never change in my life time but you can deal in estimate as to the amp or watt rating of motors which will
be stated on the motor or you can take the amp readings from the motor with a clamp meter and use the real amp reading to compare
with. Most all people here on the group does not have the tools to get the real reading from the motor to get the amp draw and
convert to watt hours. So the general public without getting all the equipment to work with can go by the Name tag amp or watt
estimate stated on the motor. The ideal of not getting all balled up with a bunch of calculation. they can just go by the stated Amp
or watt draw to compare motors as to cost to operate.

So You can use the Volt X Amp = Watts rating from the name tag and get the watt or amp draw or you can get the real reading and use
the Volt X amps = watts to get the real reading from the motor. The Name tag amp or watt rating will alway be higher but you can
alway just use the name tag amps rating to compare to another motor but just using name tag amps or watts as to compare them. To
compare motor I would want to use the factory set reading or rating of the motor rather than tring to take all the reading from your
motor which could have some errors in them by having to manually take all the readings. So I would say alway use the Manufactors set
readings of the motor being run at 100% of the motors ability. These Manufactors are always better at setting the amp draw of a
motor at 100% of it's ability that you or I can get. For a set point , Use the Manufactors Reading to compare with.

TURTLE


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.711 / Virus Database: 467 - Release Date: 6/25/2004


Hi,
All I am saying is Volt x Amp is comprised of resistive Watts which is
producing work and reactive Watts which is wasted. Ratio of this two is
power factor in another expression. Real world estimation or whatever is
still based on theory. If you don't know theory or ignore it, sooner or
later you get into trouble. Worst case, fire, or getting someone killed.
That someone could be you. I hope not.
Tony

Hi,
All I am saying is Volt x Amp is comprised of resistive Watts which is
producing work and reactive Watts which is wasted. Ratio of this two is
power factor in another expression. Real world estimation or whatever is
still based on theory. If you don't know theory or ignore it, sooner or
later you get into trouble. Worst case, fire, or getting someone killed.
That someone could be you. I hope not.
Tony


Tony, it seems you've got good intentions here, but please remember:

The original question was about efficiency and not safety. UL ratings in the
US rate an appliance at X watts for the absolute possible worst case
scenario. Pf, service inductance, and other factors are used for when you're
trying to squeeze the most out of your energy dollar, or engineering new
equipment. When that nameplate goes on any appliance that's UL listed, rest
assured the current ratings displayed there are the absolute highest that
piece can possibly consume.

BTW, the National Electrical Code dictates that we must provide for that
nameplate rating... plus 20 percent... to make it safe.

I'm certain everything Turtle does is safe, and I'm certain everything I do
is safe. The question was simply about efficiency.

We know theory, and how it's applied in the real world. Apparently you're
mssing that part.

Jake

Jake wrote:

Hi,
All I am saying is Volt x Amp is comprised of resistive Watts which is
producing work and reactive Watts which is wasted. Ratio of this two is
power factor in another expression. Real world estimation or whatever is
still based on theory. If you don't know theory or ignore it, sooner or
later you get into trouble. Worst case, fire, or getting someone killed.
That someone could be you. I hope not.
Tony



Tony, it seems you've got good intentions here, but please remember:

The original question was about efficiency and not safety. UL ratings in the
US rate an appliance at X watts for the absolute possible worst case
scenario. Pf, service inductance, and other factors are used for when you're
trying to squeeze the most out of your energy dollar, or engineering new
equipment. When that nameplate goes on any appliance that's UL listed, rest
assured the current ratings displayed there are the absolute highest that
piece can possibly consume.

Hi,
I don't think so. Look at a motor for an example. Does it show start
surge current? You said absolute highest.
I am military background. Most of my life I wokred on mil-spec stuffs.
Quite different from commercial ones.
Tony


BTW, the National Electrical Code dictates that we must provide for that
nameplate rating... plus 20 percent... to make it safe.

I'm certain everything Turtle does is safe, and I'm certain everything I do
is safe. The question was simply about efficiency.

We know theory, and how it's applied in the real world. Apparently you're
mssing that part.

Jake

Tony,

It seems you need some help here. If you were in the military, for the US or
one of our allies... Thank You.

Looks like you're coming from Canada, so you may have some trouble
understanding what I'm saying.

Please feel free to e-mail me off list and I'll be happy to continue this
discussion further.

Jake

"Tony Hwang" wrote in message
news:ulKDc.882796$Pk3.372337@pd7tw1no...
Jake wrote:

Hi,
All I am saying is Volt x Amp is comprised of resistive Watts which is
producing work and reactive Watts which is wasted. Ratio of this two is
power factor in another expression. Real world estimation or whatever is
still based on theory. If you don't know theory or ignore it, sooner or
later you get into trouble. Worst case, fire, or getting someone killed.
That someone could be you. I hope not.
Tony



Tony, it seems you've got good intentions here, but please remember:

The original question was about efficiency and not safety. UL ratings in
the
US rate an appliance at X watts for the absolute possible worst case
scenario. Pf, service inductance, and other factors are used for when
you're
trying to squeeze the most out of your energy dollar, or engineering new
equipment. When that nameplate goes on any appliance that's UL listed,
rest
assured the current ratings displayed there are the absolute highest
that
piece can possibly consume.

Hi,
I don't think so. Look at a motor for an example. Does it show start
surge current? You said absolute highest.
I am military background. Most of my life I wokred on mil-spec stuffs.
Quite different from commercial ones.
Tony


BTW, the National Electrical Code dictates that we must provide for that
nameplate rating... plus 20 percent... to make it safe.

I'm certain everything Turtle does is safe, and I'm certain everything I
do
is safe. The question was simply about efficiency.

We know theory, and how it's applied in the real world. Apparently
you're
mssing that part.

Jake

"Tony Hwang" wrote in message newsVJDc.882491$Pk3.107411@pd7tw1no...
TURTLE wrote:

"Tony Hwang" wrote in message news:l5CDc.909871$oR5.99416@pd7tw3no...

wrote:


Jake wrote:



kWh is power in Thousands of Watts, expressed over time.


That might work, if "expressed over" means "multiplied by" :-)
But I don't like the first part ("kWh is power..."), since
kilowatt-hours (and Btus) are a measure of energy, not power.



Watts are expressed as Amps x Volts.(for single phase, but let's not
complicate it further).


watts = amps x volts x power factor. This can make a big difference.
Some undercounter fluorescent fixtures have a power factor of 0.4.



IE An air conditioner consuming 10 amps at 120 volts consumes 1,200 watts.


Only if the power factor is 1.0.



The term "Watts" defines "True Power", and Turtle's explanation is correct.

5 amps x 240 volts = 1,200 watts
10 amps x 120 volts = 1,200 watts.


Only if the power factor is 1.0.



...please don't ever, ever, ever use an extension cord without
talking to an electrician first.


Would you be an electrician, by chance? :-)

Nick


Hi,
Again Volt x Amp and Watt is two different thing. Watt rating is always
less than Volt x Amp.
This is such a basic thing in theory, Sigh!
Tony



This is Turtle.

Tony You lost the Battle here with your theory. Theory only is good in Estimates and not in Readings from the Equipment it is
really
drawing. If a Motor has a Name Tag estimated Amp draw of 5 amps per hour at 120 volts or it has a estimate of 600 watts per hour
rating. You can use the estimates but they will never be that high but will be less but will be exactly in direct proportion of
the
estimate amp or watt draw of the motor.

Volt X Amps = Watts will never change in my life time but you can deal in estimate as to the amp or watt rating of motors which
will
be stated on the motor or you can take the amp readings from the motor with a clamp meter and use the real amp reading to
compare
with. Most all people here on the group does not have the tools to get the real reading from the motor to get the amp draw and
convert to watt hours. So the general public without getting all the equipment to work with can go by the Name tag amp or watt
estimate stated on the motor. The ideal of not getting all balled up with a bunch of calculation. they can just go by the stated
Amp
or watt draw to compare motors as to cost to operate.

So You can use the Volt X Amp = Watts rating from the name tag and get the watt or amp draw or you can get the real reading and
use
the Volt X amps = watts to get the real reading from the motor. The Name tag amp or watt rating will alway be higher but you can
alway just use the name tag amps rating to compare to another motor but just using name tag amps or watts as to compare them. To
compare motor I would want to use the factory set reading or rating of the motor rather than tring to take all the reading from
your
motor which could have some errors in them by having to manually take all the readings. So I would say alway use the Manufactors
set
readings of the motor being run at 100% of the motors ability. These Manufactors are always better at setting the amp draw of a
motor at 100% of it's ability that you or I can get. For a set point , Use the Manufactors Reading to compare with.

TURTLE

Hi,
All I am saying is Volt x Amp is comprised of resistive Watts which is
producing work and reactive Watts which is wasted. Ratio of this two is
power factor in another expression. Real world estimation or whatever is
still based on theory. If you don't know theory or ignore it, sooner or
later you get into trouble. Worst case, fire, or getting someone killed.
That someone could be you. I hope not.
Tony


This is Turtle.

Would you care to try to explain what you just told me to the Original Poster as to cost to operate the window unit on 120 volts or
220 volts. He / She would have no ideal of what your saying here. You can get complex with electricians but Home owners will look at
you funny and Say Yea Right.

TURTLE


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.711 / Virus Database: 467 - Release Date: 6/25/2004

"Tony Hwang" wrote in message news:ulKDc.882796$Pk3.372337@pd7tw1no...
Jake wrote:

Hi,
All I am saying is Volt x Amp is comprised of resistive Watts which is
producing work and reactive Watts which is wasted. Ratio of this two is
power factor in another expression. Real world estimation or whatever is
still based on theory. If you don't know theory or ignore it, sooner or
later you get into trouble. Worst case, fire, or getting someone killed.
That someone could be you. I hope not.
Tony



Tony, it seems you've got good intentions here, but please remember:

The original question was about efficiency and not safety. UL ratings in the
US rate an appliance at X watts for the absolute possible worst case
scenario. Pf, service inductance, and other factors are used for when you're
trying to squeeze the most out of your energy dollar, or engineering new
equipment. When that nameplate goes on any appliance that's UL listed, rest
assured the current ratings displayed there are the absolute highest that
piece can possibly consume.

Hi,
I don't think so. Look at a motor for an example. Does it show start
surge current? You said absolute highest.
I am military background. Most of my life I wokred on mil-spec stuffs.
Quite different from commercial ones.
Tony


This is Turtle.

Can you start by Explaining Surge Current to the Original Poster / Just a Home Owner and how it plays into the use of electricity in
a very simple terms that they can understand. If you try to get to spec.ing everything out you will loose the home owner in the dust
behind you. The original poster probley has no ideal what we are talking about here. When you talk over a home owners head. He just
says Yea , Right , OK.

TURTLE


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.711 / Virus Database: 467 - Release Date: 6/25/2004

"Jake" wrote in message news:qIFDc.162539$3x.9755@attbi_s54...
Boy, Nick... you sure are impressive. I'll bet you don't have a mirror in
your house that's good enough to display your perfect image. I'll bet you're
a real blast at parties, though.

I'm surprised you could take time away from your job at NASA to display your
great intelligence here.

Thank you not,

Jake

This is Turtle.

Now you know why he is in my Kill file !

TURTLE


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.711 / Virus Database: 467 - Release Date: 6/25/2004

In article ulKDc.882796$Pk3.372337@pd7tw1no, Tony Hwang wrote:
Jake wrote:

The original question was about efficiency and not safety. UL ratings
in the US rate an appliance at X watts for the absolute possible worst
case scenario. Pf, service inductance, and other factors are used for
when you're trying to squeeze the most out of your energy dollar, or
engineering new equipment. When that nameplate goes on any appliance
that's UL listed, rest assured the current ratings displayed there are
the absolute highest that piece can possibly consume.

Hi,
I don't think so. Look at a motor for an example. Does it show start
surge current? You said absolute highest.

I'm sure he meant the highest current sustained long enough to affect
the ultimate temperature of the wires that have to carry that current.
If a motor draws 10 amps continuously, any 12 gauge wire carrying that
current will not get any hotter (but will aproach whatever the final
temperature is very slightly more quickly) if that motor draws 100 amps
for 1/4 second while starting than if it's current consumption does not
exceed 10 amps when starting.

Incandescent lightbulbs often draw, usually for no more than a few
milliseconds, a peak current 10-15 times their steady-state current when
they start.

- Don Klipstein )

Jake wrote:

The original question was about efficiency and not safety. UL ratings in the
US rate an appliance at X watts for the absolute possible worst case
scenario. Pf, service inductance, and other factors are used for when you're
trying to squeeze the most out of your energy dollar, or engineering new
equipment. When that nameplate goes on any appliance that's UL listed, rest
assured the current ratings displayed there are the absolute highest that
piece can possibly consume.

BTW, the National Electrical Code dictates that we must provide for that
nameplate rating... plus 20 percent... to make it safe.

I recall 25%. Where does the NEC mention 20%?

Would you have a chapter and verse?

Nick

I recall 25%. Where does the NEC mention 20%?


You are talking about the same thing.

If a motor's FLA is 80% of the conductor's ampacity (20% safety factor) the
conductor's ampacity is 125% of the FLA.

According to TURTLE :

Turtle, I'm not contradicting you, I just thought I'd extend your answers
a bit.

Yes Electric company want to talk in KWH and not in amps. You can covert amp to KWH if you like for they are
directly convertiable.

Not quite - power factor etc., but, given otherwise identical appliances on
120V versus 240V that behave exactly the same way, power factor going to be
the same in both cases, and thus irrelevant.

So I see no difference in the cost being lower for 220 volt service verses
120 volt service.

Exactly: the same unit at 120V and 240V is going to consume the same amount of
power - the latter at half the amperage and double the voltage of the former,
and thus the same Kwh consumed.

But there are _some_ differences, whether the differences are significant
enough to matter depends on many things.

The 120V vs. 240V line-loss isn't necessarily insignificant, even well
under circuit capacity.

Ie: given the exact same wire-size between a 120V and 240V circuit
(which'll be often the case with a window-mount AC), the 240V circuit
will lose 1/4 as much power to supply line losses as the 120V circuit
does. At, say, 120V/10A with a circuit long enough for a 3V voltage
drop, that's 30W at 120V, but only 7.5W at 240V. 30 hours of that at
120V is about 1 Kwh of lost-inside-house-walls power. 8-16 cents/day,
vs 2-4 cents/day. That may or may not be significant depending on your
own personal criteria.

There is also a second effect - higher percentage-wise line losses mean
longer startup (when the current skyrockets for a brief time) surge.
Which represents increased stress on the motor and potentially decreased
lifetime. But usually not significant enough to matter - even on
AC compressors where the initial startup is about as hard as it gets.

[It'll be seldom possible to use a smaller wire size for a 240V
circuit on a window-sized AC. If it'll fit on a 120V circuit,
the minimum wiresize at 240V is (usually) the same size anyway.]

It's probably also true that those companies building 240V units
are engineering for a different market than the typical consumer.

The typical consumer wouldn't be able to use one because it doesn't
have a 120V plug.

Thus at 240V there's probably fewer models available, but generally higher
true efficiency and longer life, because these are slightly more
"commercial"/"industrial" in intent. At a higher cost of course.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.

"Chris Lewis" wrote in message ...
According to TURTLE :

Turtle, I'm not contradicting you, I just thought I'd extend your answers
a bit.

Yes Electric company want to talk in KWH and not in amps. You can covert amp to KWH if you like for they are
directly convertiable.

Not quite - power factor etc., but, given otherwise identical appliances on
120V versus 240V that behave exactly the same way, power factor going to be
the same in both cases, and thus irrelevant.

So I see no difference in the cost being lower for 220 volt service verses
120 volt service.

Exactly: the same unit at 120V and 240V is going to consume the same amount of
power - the latter at half the amperage and double the voltage of the former,
and thus the same Kwh consumed.

But there are _some_ differences, whether the differences are significant
enough to matter depends on many things.

The 120V vs. 240V line-loss isn't necessarily insignificant, even well
under circuit capacity.

Ie: given the exact same wire-size between a 120V and 240V circuit
(which'll be often the case with a window-mount AC), the 240V circuit
will lose 1/4 as much power to supply line losses as the 120V circuit
does. At, say, 120V/10A with a circuit long enough for a 3V voltage
drop, that's 30W at 120V, but only 7.5W at 240V. 30 hours of that at
120V is about 1 Kwh of lost-inside-house-walls power. 8-16 cents/day,
vs 2-4 cents/day. That may or may not be significant depending on your
own personal criteria.


This is Turtle.

What your saying here is a condition that most of the time will not be in effect for Electrician will size wire for a little more
than the max the wire will handle. If you had a 3 volt drop on a 120 volt circuit. Your taxing the wires ability atleast and need to
change the wire out to not even have a 3 volt drop to start with. If you don't give a damn about a job. You just put the least it
will get by with and let the customer pay for it the rest of their life. Any circuit with a 10 amp draw on it needs atleast a # 12
wire on it 120 volts or 220 volts. I run circuits for my equipment and if I see a 3 volt drop. i would change out the wire atleast
to not have it. I would have nothing with a 3 volt drop on it.

Now the Thread is a Home owner asking about it cost 1/2 the power cost to run the equipment on 220 volts verses 120 volt service.
You pay ruffle the same as 220 volt or 120 volt service. 1/2 the cost to operate is not in the picture.

TURTLE


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.711 / Virus Database: 467 - Release Date: 6/25/2004

Jake posted for all of us....

Boy, Nick... you sure are impressive. I'll bet you don't have a mirror in
your house that's good enough to display your perfect image. I'll bet you're
a real blast at parties, though.

I'm surprised you could take time away from your job at NASA to display your
great intelligence here.

Thank you not,

Jake


Jake, you are not going to get anywhere with these turds. They know a little
bit about something and exploit that. Then will twist and squirm like a snake
to make their point and return to it disregarding practical experence and common
sense. Don't bother; they are like DisregardDave in a lot of ways. You and the
shelled one will never get thru to them.
--
Tekkie

TURTLE posted for all of us....


"Jake" wrote in message news:EdoDc.116327$HG.9377@attbi_s53...
So what, you dumb jerk !! Explain why this is an advantage?

Jake


This is Turtle.

The only referrence Dave can refer to this is in the Hacker's Almanic 2004 edition . Jake do you subscribe to the Hacker's Almanic
like Dave does ? I had to give up my subscription because of the every year when your fee / cost comes due you have to send in
something stupit you did and the fee is wavered. I was not going to lie to making me not pay. Dave can lie and be straight faced
about it and gets it free.

TURTLE

DaveinHackerville and the Stumped Moron are editor & publisher with lifetime
subscriptions aren't they?
--
Tekkie

m Ransley posted for all of us....

I thought Dave was the Editor and founder of the Hackers Almanac.


Sorry mark hadn't read this far down...
--
Tekkie

According to TURTLE :
The 120V vs. 240V line-loss isn't necessarily insignificant, even well
under circuit capacity.

Ie: given the exact same wire-size between a 120V and 240V circuit
(which'll be often the case with a window-mount AC), the 240V circuit
will lose 1/4 as much power to supply line losses as the 120V circuit
does. At, say, 120V/10A with a circuit long enough for a 3V voltage
drop, that's 30W at 120V, but only 7.5W at 240V. 30 hours of that at
120V is about 1 Kwh of lost-inside-house-walls power. 8-16 cents/day,
vs 2-4 cents/day. That may or may not be significant depending on your
own personal criteria.

What your saying here is a condition that most of the time will not be
in effect for Electrician will size wire for a little more than the max
the wire will handle. If you had a 3 volt drop on a 120 volt circuit.
Your taxing the wires ability at least and need to change the wire out
to not even have a 3 volt drop to start with.

10A is well within the rated ampacity of even a 14 ga circuit even after
80% derating, and 3V is _less_ than both the NEC or CEC IR drop maximum.

If you don't give a damn
about a job. You just put the least it will get by with and let the
customer pay for it the rest of their life. Any circuit with a 10 amp
draw on it needs atleast a # 12 wire on it 120 volts or 220 volts. I
run circuits for my equipment and if I see a 3 volt drop. i would
change out the wire atleast to not have it. I would have nothing with a
3 volt drop on it.

I have no quibble with the fact that you'd consider a 3V drop excessive,
and would up the wire. And indeed, for built-in central A/C, I think
any good electrician or HVAC installer should and would consider doing
exactly that.

However, we must face reality here. In the vast majority of mass built
homes, electricians are often simply not going to think about this at all
for general circuits (the context being, I think, a window-mount A/C
on a general outlet circuit). And of those that do, few would consider
a 3V drop excessive either.

Not to mention the startup surge, which will probably at least triple
the drop momentarily (triple power loss and increased compressor start stress).

Now the Thread is a Home owner asking about it cost 1/2 the power cost
to run the equipment on 220 volts verses 120 volt service.

No, we got one of the answerers suggesting that. Once you exclude
that bit of nonsense (which seems to pop up every time someone asks about
120V vs. 240V - I think the stupidity level is remaining constant
despite everyone correcting them EVERY time), a few percent of power
lost in the wiring MAY well be significant to the OP.

And do remember that that, say, 3% loss to supply wire heating may increase
total power consumption by more than the 3%. If you lose 3% heating up the
supply lines, another 3% of your A/C capacity may get chewed up trying to
get rid of it, so the inefficiency could theoretically double.

[worst case, exceedingly unlikely in practise, but you get the idea.]

You pay
ruffle the same as 220 volt or 120 volt service. 1/2 the cost to
operate is not in the picture.

Absolutely. But I don't think that's where the OP was, nor what they
were thinking, just one of the more ignorant responses.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.

"Chris Lewis" wrote in message ...
According to TURTLE :
The 120V vs. 240V line-loss isn't necessarily insignificant, even well
under circuit capacity.

Ie: given the exact same wire-size between a 120V and 240V circuit
(which'll be often the case with a window-mount AC), the 240V circuit
will lose 1/4 as much power to supply line losses as the 120V circuit
does. At, say, 120V/10A with a circuit long enough for a 3V voltage
drop, that's 30W at 120V, but only 7.5W at 240V. 30 hours of that at
120V is about 1 Kwh of lost-inside-house-walls power. 8-16 cents/day,
vs 2-4 cents/day. That may or may not be significant depending on your
own personal criteria.

What your saying here is a condition that most of the time will not be
in effect for Electrician will size wire for a little more than the max
the wire will handle. If you had a 3 volt drop on a 120 volt circuit.
Your taxing the wires ability at least and need to change the wire out
to not even have a 3 volt drop to start with.

10A is well within the rated ampacity of even a 14 ga circuit even after
80% derating, and 3V is _less_ than both the NEC or CEC IR drop maximum.

If you don't give a damn
about a job. You just put the least it will get by with and let the
customer pay for it the rest of their life. Any circuit with a 10 amp
draw on it needs atleast a # 12 wire on it 120 volts or 220 volts. I
run circuits for my equipment and if I see a 3 volt drop. i would
change out the wire atleast to not have it. I would have nothing with a
3 volt drop on it.

I have no quibble with the fact that you'd consider a 3V drop excessive,
and would up the wire. And indeed, for built-in central A/C, I think
any good electrician or HVAC installer should and would consider doing
exactly that.

However, we must face reality here. In the vast majority of mass built
homes, electricians are often simply not going to think about this at all
for general circuits (the context being, I think, a window-mount A/C
on a general outlet circuit). And of those that do, few would consider
a 3V drop excessive either.

Not to mention the startup surge, which will probably at least triple
the drop momentarily (triple power loss and increased compressor start stress).

Now the Thread is a Home owner asking about it cost 1/2 the power cost
to run the equipment on 220 volts verses 120 volt service.

No, we got one of the answerers suggesting that. Once you exclude
that bit of nonsense (which seems to pop up every time someone asks about
120V vs. 240V - I think the stupidity level is remaining constant
despite everyone correcting them EVERY time), a few percent of power
lost in the wiring MAY well be significant to the OP.

And do remember that that, say, 3% loss to supply wire heating may increase
total power consumption by more than the 3%. If you lose 3% heating up the
supply lines, another 3% of your A/C capacity may get chewed up trying to
get rid of it, so the inefficiency could theoretically double.

[worst case, exceedingly unlikely in practise, but you get the idea.]

You pay
ruffle the same as 220 volt or 120 volt service. 1/2 the cost to
operate is not in the picture.

Absolutely. But I don't think that's where the OP was, nor what they
were thinking, just one of the more ignorant responses.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.

This is Turtle.

I don't do window units anymore and have cut the residentiual customers down to little as possible. If I do a commercial new
installation or residentiual new I have a talk with the electrician on the wire size to my stuff. I tell the customer if the
electrician does not listen to me and will tell the customer that I will do the Electric work to my stuff for the Electrician is not
listening to me. If you can't put good wire to my stuff. You don't need me to do your work. Most all the Electricians in the area
knows me and I don't even have to say anything if they know I'm doing the Air.

You better figure out people on this alt.home.repair before you assume they are very knowledgiable about 220 volt and 120 volt
service. Judging Ignorant responces here can get you in trouble. You better clear the air right off even when it may not be the case
for Assuming anything here will get someone hurt. You better say it in all cases to be sure. Now if you want to hear a joke read
what HVAC fella told the OP and the OP did not say a word. The OP did not say anything as to it being their thoughts or not. Watch
out Assuming anything here.

TURTLE


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.711 / Virus Database: 467 - Release Date: 6/25/2004

According to TURTLE :

You better figure out people on this alt.home.repair before you assume
they are very knowledgiable about 220 volt and 120 volt service. Judging
Ignorant responces here can get you in trouble. You better clear the air
right off even when it may not be the case for Assuming anything here
will get someone hurt. You better say it in all cases to be sure.

Having been on _these_ groups for 14 some-odd years, it's a matter of
course to assume the worst, reading all of the postings first and realizing
that 3-4 people had already stomped on the stupid idea, just means you
can avoid the noise and give the real story on differences between 120V
and 240V.

OP did not say anything as to it being their thoughts or not.

That's pretty typical here. Ask a question and not indicate that they've
read or understood the followups. There's enough noise, no need to add
to it.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.

Is Chris Lewis stating 240 wire- line is more efficient than 120.
There is less line loss.? I find that impossible to beleive or we
would give ourselves the option of converting and getting all 240
inhouse as Europe is.

m Ransley wrote:
Is Chris Lewis stating 240 wire- line is more efficient than 120.
There is less line loss.? I find that impossible to beleive or we
would give ourselves the option of converting and getting all 240
inhouse as Europe is.

Hi,
Of course. Think about HT transmission lines. Why do you think they use
such a high voltage? For better efficiency. Likewise............
Tony

Better efficiency ? you mean smaller cable. Cheaper long distance
transmission. Or why doesnt Energy Star , EPA and every green
orginiation admonish us from being 120. I can easily but a 240
Frige, TV, AC anything I want. I hear nothing about Americas 120 v
system. 240 is jn in every house , if it made 1% difference then off
grid Solar , Wind generation, and greens off grid would talk 240 all
day long, they dont. If that were true where is 480 AC So Im
listening , and willing to learn.

m Ransley wrote:

...why doesnt Energy Star , EPA and every green orginiation admonish us
from being 120. I can easily but a 240 Frige, TV, AC anything I want.

The US picked 120 as a safety compromise. Less efficient, with fewer dead
people. France did the same, then doubled the voltage to raise grid capacity.

Nick

According to m Ransley :
Is Chris Lewis stating 240 wire- line is more efficient than 120.
There is less line loss.?

Absolutely. Given the same wiresize, the same power delivery loses
four times as much in line losses at 120V as it does at 240V.

Remember that most circuits we're dealing with are already at the minimum
permissible wiresize, so going to 240V won't save anything in copper.

I'd be the first to suggest that the efficiency difference is minimal,
and almost never worth worrying about. But when someone _is_ in a position
to make the choice, they should get the full answer so they can make
an informed choice.

I find that impossible to beleive or we
would give ourselves the option of converting and getting all 240
inhouse as Europe is.

Every country has to answer for themselves what compromises they want to
make - cost, safety, taking into account user patterns, history and so on.

Switching to 240V, for example, would likely end the use of edison base
lamps and full rewiring of existing houses. Imagine how much _that_
would cost....
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.

AC/DCdude17 wrote:

" # Energy requirements: 120 Volts / 60 Hertz, 1665 Watts, 12.0 Amps "

They must have been smoking something when they wrote that.

120V * 12A can't equal more than 1440W PERIOD. That's just physics.

And that VA (vs watts) is power, not energy.

Nick