# What is power factor, anyhow?

Yes, I agree. We're thinking the same thing, but I was a little off there too :) After doing the integral, you do have to divide by the time interval, whether it's one cycle or one sec, etc.
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On 12/30/2009 02:30 PM, David Nebenzahl wrote:

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The best way to think of it is that a load with a low power factor will move a lot of electricity back-and-forth in the power lines without actually consuming the energy. You get billed for the amount of power the load uses, but a higher amount if moving back-and-forth, and being disipated as heat in the power lines, transformers and so on. So, there's a real cost to the electricity company, but it doens't show on the meter. That's why larger industrial users with poor power factors will be charged for it, and why some install local capacitors to act as reservoirs to restrict the back-and-forth to their own premises, thereby avoiding all the waste in the power transmission system.
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On 12/31/2009 11:05, Mike Granby wrote:

The power companies install capacitors to introduce capacitive reactance to bring the PF closer to unity in the upstream transmission lines.
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Way to take a simple explanation and make it complicated, George...
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In wrote:

Umm, haven't you ever noticed the large banks of capacitors housed outside many industrial buildings? THOSE are the ones that are correcting for the PF in that building. The power company does not correct for unknown power factors and couldn't if it wanted to. I think you're misunderstanding the purpose of whatever it is you're seeing that you think are cap banks.
Twayne
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Twayne wrote:

Don't know about where you live, but around here I often see racks of PF correction caps on utility poles - 3 phase distribution voltage. Utilities certainly DO install them. Utilities may also switch PF correction caps [which can cause bad surges].
Another good post by George. Another bad one by Twayne.
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In wrote:

Utilities -sometimes- may install them in certain areas, I don't know. I've never seen it in Coronado, San Diego, Chicago, Aspen, Fort Worth, St. Louis, Boca Raton, or upsate NY and NYC. Anymore it's all underground anyway except for smaller cities and rural areas. I've seen a lot of things on power poles but never a capacitor bank. Once the plans are approved for their installation by the powerco, a contractor installs them any where I've ever been. Then they're inspected by the powerco if it's a big system and they go into use. One of the things you do often see on a power pole is a repeater for sending the RF received electrical usage down down the hi-voltage wires for charging for power purposes.
I'd appreciate it if you could find a URL or similar source to verify that they'll put capacitor banks on a power pole. You do realize how much even small ones weigh, don't you? And what the value of "small" would be? I'm guessing you don't, but it's easy to calculate. Actually I'm wondering now if you would even recognize a capacitor bank as capacitors anyway. But, if I'm wrong, I'd certainly like to see some evidence of it.
Twayne
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Often you'll find excellent advice on a newsgroup.
Before you use that advice though, consider the
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Twayne wrote:

Out of some 16,000 hits on "capacitor+bank+power+poles" here's the first - complete with pictures:
http://www.nepsi.com/ptcb.htm
Here's a brochure (PDF) with really colorful pictures (suitable for framing) http://www05.abb.com/global/scot/scot245.nsf/veritydisplay/8c7b7a25f95d7c0ac12570fa002420ca /\$File/Qpole%20Pole%20Mount%20Brochure.pdf
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In typed:

http://www05.abb.com/global/scot/scot245.nsf/veritydisplay/8c7b7a25f95d7c0ac12570fa002420ca /\$File/Qpole%20Pole%20Mount%20Brochure.pdf
OUTstanding, heybub! Thanks for the education, really. I have never seen them and if I had I'd be sure to have remembered them! At first I thought they might be all Pac Rim and EU located, but no, there are a few for N.A. too, so obviously they are used here, IMO.
I sincerely apologize to you; hope you'll accept it. I was wrong and made suppositions I shouldn't have. I was surprised to see polyprop as the material, too. Guess I shoulda known better; next time I'll be a lot more careful.
Twayne
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Live in the moment;
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Twayne wrote:

I first saw a rack of PF correction caps about 5th grade. The utility was installing one on a utility pole next to my school. I asked a lineman what it was and he told me. Even explained what it did, but in 5th grade it didn't entirely make sense - current when there is no voltage???
That rack, and the racks I see about every day, look a lot like the .htm from HeyBub. The racks may have 3, 6 or 9 caps.

Gotta be way lighter than 3 pole pigs for 3 phase.

ooh - nobody is as smart as Twayne. I have know what PF correction caps look like since I was about 10. Maybe you don't know what they look like.

HeyBub to the rescue after a difficult google search.
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Ouch!
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On 12/31/2009 19:50, Twayne wrote:

But the power company commonly corrects for PF and does install capacitors to do it. They know practically none of their customers have a unity PF and are usually lagging. Their base charges already include an allowance for that. Not sure why they couldn't correct PF if they wanted to since all they need to do to correct the typical lagging load connected to them is install capacitors just like a large industrial facility might if they want to avoid a PF penalty.
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On 12/31/2009 17:24, Mike Granby wrote:

One of the reasons everyone is so confused is trying to develop a trivial explanation for something complicated.
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It isn't complicated. Like I said, certain loads put a strain on the trasnmission system without actually using power. That's all that has to be said. All this show-boating about phase angles, reactance and moving the PF back to unity is what is getting in the way.
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On 1/3/2010 09:10, Mike Granby wrote:

So your opinion trumps everyone then? Suppose someone wanted to actually understand what was happening rather than the trivialized don't know any more than you did before you read it explanation?
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George wrote:

Well, if one can't understand the problem, he just has to take the word of his betters. I guess.
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George wrote:

"Those who say a job is too difficult simply haven't tried hard enough." [Ronald Reagan]
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Power Factor is related to inductive or capacitive loads. It is best seen if you take it to an extreme with a load that is 100 capacitive. Lets say you put a capacitor across the line and measure the current at 10 amps. This current is not doing any work and is returned to the circuit. It doesnt show up on your electric bill and is not read by your power meter. This is only more or less true. The more or less part come in because the cables that carry the current to and from this capacior are not perfect conductors, they are resistive. The increased current caused by the capacitor increases loss on the lines. These losses turn into heat which you will have to pay for. For resisdential use it wont be very much for industrial use it could be quite a bit. PoCos also have extra charges for places who have a highly reactive load because it causes greater losses on the PoCo's power lines. Their are lots of myths that you can add capacitors or inductors to reduce your eelctric bill and even get free electricity. Neither are practical for residetial users. The free electricity myth isnt true for any type of user.
Jimmie
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In wrote:

Eggzactly. Well put too.
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