Is Kill-a-Watt the best electricity measuring tool?

[Googer]

You could make your own semi-portable watt meter for just a few bucks. You will need:

A few feet of heavy gauge wire.
An old out door electrical meter.
A brand new Juntion box.
An new outlet (avalable from the hardware store)
A brand new Universal 3 prong plug
You will also need the box that the meter connects to (I do not know the name).
Directions are self expanitory .

On the power input side,Add a power cord with plug to the electrical meter (after it has been installed in a housing). This is the side where it would be connected to the telephone pole.
Then add a few feet of wire to the output side and attach the meter to one end and the junction box with outlets to the other. (This is the side where the line beteween the house and box would normaly go)
Final Step- Pat yourself on the back and give credit to my Idea.
Voila, you have yourself one homebuilt power measurement meter.


I will say that newer Kw/H home meters are probably more accurate than the old ones. If you can find a newer one for cheap then use it.


If you cannot figure it with out directions from the list of parts above them you should not play around with electricy, give the parts to an electrican and have him do it for you.

http://www.infinigi.com/sunwize-kwhr-meter-p-99.html?ref=100

 

[Navid]

Originally posted by: Googer
Multiply the AMP x Volt = the wattage being consumed.

Unfortunately, that would be Apparent power, which by the way as you pointed out is reported in Volt Amps.

The Wattage being consumed (Real power) could be anywhere between 0% to 100% of that, depending on the power factor.

 

[Navid]

To those who keep talking about PFC, this discussion has nothing to do with PFC!

PFC (power Factor Correction) is the effort, or capability, to adjust the effective power factor of a load.

We are talking about measuring the power used by an electric load (like your PC). If a device has a power factor other than 1, it gives some power back to the power grid. So, the power it uses (Real power in Watts) is a percentage of the power it receives (Apparent power in Volt Amps).

Whether PFC is good or useless, is a very interesting subject, although irrelevant to how you can accurately measure the consumed power!

 

[Navid]

Originally posted by: Apocalypse

Originally posted by: Navid

Originally posted by: furballi
Never said P=VI is 100% valid for AC circuit! And I don't need Physics 101 lessons. Perhaps it is YOU who may require a refresher in English 101. Do you understand the word "adequate"?

I am the one who is looking for a way to measure power and reading 480W when it is really 336W is not "adequate" for me.
Chill out, or else, you will get old fast. lol!

well learn to read and all will be well!!

Furbali never gets old and his advice is usally pretty right on.

I have been pointing out the fact that there is a difference between Apparent power and Real power.

If you can see any explanation in this thread on why consumed power is equal to measured RMS voltage multiplied by RMS current, and Apparent power is just a sham, I promise you to read it.

I am not interested in arguing and getting personal. I post here because I like to learn.

 

[furballi]

In the best case scenario, PFC will not change the efficiency of the PSU for the home user. Most of the time, the PFC circuit will result in a small drop in efficiency of the PSU. Again, we're comparing a PSU with and without PFC, and no other change to the PSU.

Many quality PSUs sold in the US are rated at 80 to 85% efficiency. Adding PFC circuit is a marketing tool. Those same units are sold in the EU with the PFC circuitry added because it is mandaded by law. No other mods are made to the PSU!

 

[Googer]

I would say the Kill-a-watt is the better of the two devices. The Seasonic Power Angel has an accuracy of 2% and the Kill-A-Watt is ten times more acurrate to with in 00.2% of the reading.


http://www.p3international.com/products/special/P4400/P4400-CE.html
http://www.seasonicusa.com/products.php?lineId=8

 

[Jiggz]

Originally posted by: Navid
To those who keep talking about PFC, this discussion has nothing to do with PFC!

PFC (power Factor Correction) is the effort, or capability, to adjust the effective power factor of a load.

We are talking about measuring the power used by an electric load (like your PC). If a device has a power factor other than 1, it gives some power back to the power grid. So, the power it uses (Real power in Watts) is a percentage of the power it receives (Apparent power in Volt Amps).

Whether PFC is good or useless, is a very interesting subject, although irrelevant to how you can accurately measure the consumed power!

This Dude got it right to the letter. PFC is more of a concern to power generation rather than power consumption. Power consume can theoretically be computed as the product of (PF) X Apparent Power or VA.

But going back to the original question, the answer is Yes! Considering it's accuracy is within 0.2% or equal to 99.80% accurate.