"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