"Pop" wrote in message
...
Hi all,
As I recall there are a few people here with the expertise to
answer these questions easily. Simple 4 u, not 4 me! g
Yes, I've done a bunch of googling and recalling the "old
school days", but it's not getting me where I need to be g.
Neglecting small interferences/insertion losses, etc.:
--------------------------------
Short description:
Here's an actual example of measurements/calcs:
120Vac measured
0.29A rms measured
24W measured
35 VA measured
PF = W / VA, or 24 / 35 = 0.686..., or about 68%. Right?

-- What numbers do I use to get kWH? Is it VA / W?

-- How many kWH do you calculate from those figures, assuming it
can be done? If it can't be done, what's missing?
-- How did you get to your result?

-- At 10 cents/kWH, how much would it cost me per hour?

---------- end short descrip -----------

You wouldn't believe the amount of work and research I've done to
get my head around this! And how confused I am at the moment!

All I started out to do was to calculate what some of the major
device costs around the house are in order to make a point to
some people about the cost of, say, leaving the lights on in an
unoccupied room over night, or never turning off say a coffee
maker, computers, radio, stereo, TV, holiday lights; things like
that. And I ended up with a brain-ache so I next decided to go
where there might be some brighter brain cells than my own! And
here I am!

Thanks for your hopefully understandable responses; it's been
over 4 decades since I was in college, so be kind please g!

Wellll, one more question while I have your attention: I've
always heard and read that residential homes never required power
factor adjustments of any kind because the power factors would
never get very low. If I'm interpreting my numbers right
however, I'm seeing PF numbers that are surprisingly low. Most
every home is full of motors and other inductive appliances.
How low IS a "low" power factor number?
Or do power companies account for power factors at the
facility? Just curious.

Regards,

Pop


Sounds like you have a lot of time on your hands.

Here is a link to some useful charts:
http://www.mrelectrician.tv/conversi...electrical.htm

24 watts divided by 1000 equals .024 KW times 1 hour equals .024 KWH times
10 cents per hour would cost you .0024 cents to operate for one hour. I
think.

The power company puts power factor correction equipment on their lines.