Residential & PF

Ben Miller wrote:


That reminded me of this:
MY JOB
It's not my job to run this train;
The whistle I can't blow.
It's not my place to say how far
The train is allowed to go.
It's not my job to shoot off steam
Nor even clang the bell.
But let the damn thing
Jump the track . . .
and see who catches Hell!
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------- Yes there are real electrical engineers lurking on this group. Paul H is one, Daestrom is another, Ben Miller is one. I also am one. There are others and some definitely are not engineers- wecandoit, and the guys who spend their time in infantile insults are not.
Do we deal with digital transmission lines? - I don't and some of the others don't- power transmission and utilization is far more fun.
You got a good answer to your question from Paul and Martindale pointed out some facts. In considering residential service, the charges are based on energy as read by a KWH meter which actually measures the real power* time. Your KWH meter, at .38KWH over 1.62 hours indicates an average real power of 380/1.62 #0 Watts (rounded to 2 significant figures). This meter doesn't give a hoot about power factor Your killawatt indicates 205 Watts - The KWH meter is actually more accurate by a fairly large margin (money is involved).
In determining your costs- consider only the real power as that is all that the KWH meter cares about. The power factor as found from watts/Volt amps 5/269 =0.76 as opposed to the measured 0.78 . Your voltage times current indicates 259VA not 269VA so there are a few discrepancies but this is to be expected. The measured Volt-amps includes the effect of reactive volt amps which is a measure of energy put in during part of the cycle and returned in another part of the same cycle =average of 0 (in every 1/60 second) so it doesn't register in the watt reading. This is what gives the power factor which is the ratio between true power (watts) and the apparent power or volt-amperes. Using your measurements the reactive Volt amps 4VAR The power factor of different loads will depend on the load. A light bulb or heater will be unity power factor as they are pure resistance loads. A single phase motor will have a power factor at full load of the order of 0.7 or so at full load and about 0.5 at no load because it is inductive. Fluorescent lamps have inductive ballasts so they will also have a power factor less than unity.
All this tells us nothing about the efficiency of the generator, the transmission line or even the appliance itself. At this power level trying to correct power factor (at the appliance- not at the house service entrance) might save a couple of watts (line losses as Paul had indicated) but would cost more than it saved so why bother.
Does this help?
--

Don Kelly snipped-for-privacy@shawcross.ca
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Yeah, I knew that; the comment was aimed at a few specific dunderheads, not the "real" people here. I know I shouldn't, but sometimes when I'm in a particularly good mood it's entertaining to bait them and then just ignore them<g>. That way one can rationalize that even the non-sapient beings contribute at least minimally to the group.

I thought I'd enjoy that end of things too at one time but as my health turned out it's a good thing I let them bolt my ass to a chair; I'd have never made it in the activity-oriented' world..

I know they did, and I hope my temporary rantings didn't PO them too badly. Now I'm seeing more signs of intelligent life here I just might spend some time here. I might be "old" by some standards but I can still contribute and am still looking forward to the actual retirement age. I've been "retired" for health reasons for several years but I like to keep my fingers in the pie and know a little about what's up in the industries.
...

Yes, it does Don, thanks. Your post is what I often consider the clarification/verification end of things that shows which set of answers were probably the most accurate in cases where there might be multiple camps on a subject. And I don't count non-sapients as a camp<g>.
Cheers,
Twayne
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says...
<snip>

There are several.

I am.

Of course not. Other parts of the career include things like going to meetings, training new managers, and other more difficult stuff.

"Feel" like anything you want, though you must be a Democrat.
--
Keith

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lol, hey, a sense of humor! Well, comedic at least, if nothing else. It's obvious you know the answer so I won't spoil it for those who are waiting to see what it is.

There's that sense of humor again! Heck no I ain't no Democ rat! Nor am I a Republic can! Don't you know any better than to bring religion or politics into a discussion? Gads, this thread will go on for months, now! Even a good Christian like myself knows better than that, fer cryin' out loud! I guess to be accurate you'd have to say I'm not a good Catholic OR Protestant, although I'll attend either church; but I'm a good catholic-protestant! Just keeping it accurate. So follow my lead and never, *ever* mention that kind of thing, OK?
Cheers,
Twayne
--

Children are the future;
unless we stop them now.
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