On Apr 11, 7:39*pm, gregz wrote:
Art Todesco wrote:
On 4/11/2012 12:23 PM, Doug wrote:
On Tue, 10 Apr 2012 19:03:43 -0700, *wrote:

On 4/10/2012 11:08 AM, wrote:
Another thread on here mentions using a Kill-A-Watt meter to test the
power usage of a freezer (or anything else). *I'm considering buying one
of these. *I'm sure there are many brands available. *I want something
that's functional, durable, and has the most *useful* options. *Yet cost
is a factor too. *I generally wont buy the cheapest one, but dont want
to spend a fortune on it either.

I've never used one of these, but the way I understand it, they are
plugged into an outlet and the appliance plugged into the meter.
However, what if I want to monitor the power usage in (example), my
garage/workshop. *Can this be done? *Or what if I want to monitor total
power usage in my home, going across the Mains. *I suppose some wiring
would be required, (which is no problem for me). *Another consideration,
are they only made for 120V, or can they be used for 240V such as a
dryer, elec range, or a welder?

Which brands do what?

Please include the BRAND NAME and MODEL. *Then list their FEATURES,
PRICE, and the STORE or ONLINE place that sells them.

I've messed with this a LOT.
First thing to ask yourself is, "what am I trying to accomplish?"
It's unproductive to ask a question if you're not gonna do anything
with the answer.

If you want to save money, you already know how to do that.
Just use less of everything.
It costs half as much to shower every other day. *But are you going
to shower every third day based on the reading on your meter?
A bucket, stopwatch and a thermometer will give you all the tools
you need to calculate what a shower is costing you.

Are you going to raise the internal temperature of your fridge?
Are you gonna forgo that cold can of pop 'cause it costs you $.0002
to open the fridge door?
Are you going to drink cold coffee or quit toasting your bagel?
If your welds are too strong, weld faster.
If you have electric rates that differ over the course of a day,
you can wash clothes at 4AM.

Bottom line is that we use as little as we can stand. *Using less
is not practical or we'd be doing it.

But, it is fun to look at the numbers. *Some may surprise you and
need to be dealt with. *I'd vote against long-term monitoring. *It's
not worth the expense, 'cause you're not likely to pay any attention
after the first month. *The wife is gonna' suggest that bathing more
often might help your love life...and you know what you're gonna do.

The Kill-A-Watt measures Watts and Volt-amps. *Watts is what most
utilities charge for. *It's great for learning how much money your
cable box is costing you in electricity. *But, again, are you gonna
unplug the cable box that's costing you $50/month to save a buck in
electricity?

They are marketed under several brand names. *Google will find 'em for you.
If google doesn't know, you won't likely find it for sale anyway.
I paid $2 for mine at a garage sale. *If I add up all the electricity
I saved using it, I think it'll be sometime in 2015 by the time I get
my $2 back.

A clamp-on amp meter is a useful tool for 240V devices.
It has no knowledge of power factor, so you'll only read volt-amps.
But the water heater, stove, the heater part of an electric dryer all
have a power factor of 1, so watts == volt-amps.
Isn't gonna help much with your welder, or CFL lamps, or motors.

The simplest thing to do is use the utility meter on the house.
You're monitoring exactly what you're being billed for.
A stopwatch to measure how fast the wheel goes around as you turn stuff
on/off will tell *you exactly what you're paying for.
Once you get the number, it probably won't change much. *Then, all you
need is to time how long it runs. *An electric clock on the load side of
the switch will tell you that. *Shorter showers make the water heater
run less. *But you didn't need ANY measurements to know that.

Blue-Line Innovations distributes a device that clamps on the utility
meter and watches the disk go around. Transmits wirelessly to the
readout. *They also have a computer interface.
I got mine for cheap at a garage sale. *I wouldn't pay the retail price
for one. *Again, marketed by several vendors.

If you have a digital utility meter, it likely has an infrared light
that blinks. *Mine blinks once for every watt-hour of use.
I wrote a little program that runs on a Palm III. *Point the IR sensor
at the meter and it graphs usage. *Kinda interesting to watch the
water heater go on and off. *Pretty soon, you recognize the power
signature of the water heater, microwave, furnace, etc.
I was so fascinated that it took over a week to become bored.

While I was at it, I hooked up a switch with a flapper over the vent to log
the run-time of the gas furnace. *Guess what...turning down
the thermostat saves money.

One thing you will discover is how much power is wasted by stuff
that's turned off. *Common term is "vampire" devices.
I could save about 35Watts of wasted power 24/7 by turning off
all the devices related to watching TV. *So, I put in a power
strip and switch it off when not in use.
Every time I wanted to watch TV, I had to turn on the power,
reprogram the clock on two VCR's, wait for the devices to boot
and figure out what they are...then I could watch TV. *That lasted
about a week.

IF I took all the time I've spent on measuring stuff and spent it
working at minimum wage, the money I'd earned would more than pay for
all the energy I'm ever gonna save over using common sense.

Conservation is a good thing. *Use as little as possible, but no less.
You don't need much real-time data to do that.

Yesterday I was thinking of buying this K-A-W meter but I began to
realize, I'm not going to change anything even after I see the meter's
results so why bother getting one. *I mean I always try to save
electricity in my home using age old advice so I probably have little
practical reason for this device except for the fun factor. *I'm old
enough to know by now how to save electricity without the meter and as
you pointed out, saving electricity in some cases isn't always
practical.
A lot depends on you. *I am a retired engineer. *Actually, engineers
never retire, we only bug our spouses with engineering-type stuff all
over the house. *I've had my Kill-A-Watt for about 5 years now and
probably use it once a month, on average for generally testing, etc. *I
also had a voltage problem where the power company was jacking up the
voltage, apparently to relieve low voltage problems in other parts of our
local grid. *I was up to 126 volts and sometimes higher. *It did cause
problems with at lease one piece of electronic equipment in my house.
When I called them and gave them the results, they initially brushed me
off. *But when I got to talk to an engineer, he was interested. *They
called me back about 1/2 hour later and said the problem was theirs and
it would be fixed immediately. *I actually watched the voltage go down about an hour later.

How would they do that ???

Greg- Hide quoted text -

- Show quoted text -

Normally done by changing the tappings in your local transformer.
Which might be a minor task or not depending on the design.