Electricity usage measurement

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Patrick Keith-Hynes

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Jun 4, 2001, 12:42:36 PM6/4/01
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Hello,

I have a fairly large house and farm complex and I am using way more
electricity thn I would like. I am looking for a good way to measure my
usage, circuit by circuit, including things like circulating pumps and well
pumps that are not easily unplugged.

Does anyone know of a device that I could connect (possibly at the breaker
box) with minimal wiring that would enable me to monitor power use in this
way?

Thanks in advance for the help.

Patrick Keith-Hynes
p...@together.net

Don Kulha

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Jun 4, 2001, 8:42:43 PM6/4/01
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The issue being these are intermittent loads? If so I'd likely get a AC
current clamp.to hook up to a recording meter (Fluke 87 or equivalent) to
record current flows over some period of time. A/C clamp on ammeters
themselves are pretty cheap at Radio Shack. For plug in loads up to 1850 watts
it tough to beat a Brand meter....Love mine.

Steven & Rïsé Estergreen

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Jun 5, 2001, 2:22:58 AM6/5/01
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www.onsetcomputer.com has a neat datalogger that has 4 channels of temperature,
humidity and voltage, and for which they sell a current probe which would do
what you want very well (as well as a lot of other things you could think of
once you have those capabilities). If you use a sampling rate that will give
you several hours of data, you won't necessarily get the peak current during
motor startups, etc, but that doesn't seem to be your purpose.

Steven Tjiang

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Jun 6, 2001, 8:48:12 AM6/6/01
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I am looking into power and
electricity usage measurements as well.

First, just measuring the current and voltage with
a meter and then multiplying won't give you an accurate
power value because that doesn't take into account
the power factor. The power factor accounts for
the fact that inductive loads such as motors introduce
phase shifts between the current and voltage. Meters
measure the average value of the voltage and current;
multiplying doesn't give you the average power when
a power factor is involved.

IMHO, there are two ways to do this....

1. Buy either a Brand watthour meter http://www.brandelectronics.com/
or a WattsUp? kwh meter. http://www.cetsolar.com/wattsup.htm.
Brand electronics has several models, one of which will do
logging. Both take into account power factors and give readings
in cumulative kilowatt hours but are only single phase. Both, however,
you can only use them to measure loads of less than 1850 Watts
(Brand) and 1200 (Watts Up?). They aren't designed to
be connected to your breaker box directly.

2. Buy a utility power meters (i.e. the ones with the spinning disc)
and hook up a power cord and a plug to it. These won't measure
instantaneous wattage. You could wire them to your circuit
permanently. Utility power meters can be bought on Ebay anywhere
from $10.00 to $100.00 depending on the model. This solution
will work for multiphase and high power loads but does require some
wiring work.

"Patrick Keith-Hynes" <p...@together.net> wrote in message
news:BROS6.123$N35....@nntp1.onemain.com...

Nick Pine

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Jun 6, 2001, 11:13:15 AM6/6/01
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Steven Tjiang <st...@nospam.org> wrote re:

>...a Brand watthour meter http://www.brandelectronics.com/...
>you can only use them to measure loads of less than 1850 Watts...

You can do better than that with good resolution with their
10:1 external mechanically-switchable current transformer...

Nick

Leonard Joosten

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Jun 27, 2001, 2:18:52 PM6/27/01
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Check out www.veris.com
We use the H8050 series for monitoring loads like yours. It installs real
easy and has a Form A pulse output.
You might consider the H6010 Series, It has a LCD display to show you the
kWh usage as well as the pulse output.

"Patrick Keith-Hynes" <p...@together.net> wrote in message
news:BROS6.123$N35....@nntp1.onemain.com...

HF

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Jun 28, 2001, 9:26:35 AM6/28/01
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You might also check out Onset Computer. We manufacture very low cost, data
loggers that can be used to monitor equipment run times as well as amperage
usage at the panel. Our dataloggers can be used in conjunction with user
provided sensors, as well. Veris is also very good with sensors, though they
no longer carry data loggers. Their equipment can be connected to the HOBO
data loggers for logging the monitored data.
Hope this helps!

www.onsetcomp.com


in article 3b3a2404$1...@windy.powercom.net, Leonard Joosten at
ljoo...@engagenet.com wrote on 6/27/01 2:18 PM:

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Tim Keating

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Jun 29, 2001, 11:49:24 AM6/29/01
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On Mon, 4 Jun 2001 12:42:36 -0400, "Patrick Keith-Hynes"
<p...@together.net> wrote:

>Hello,
>
>I have a fairly large house and farm complex and I am using way more
>electricity thn I would like. I am looking for a good way to measure my
>usage, circuit by circuit, including things like circulating pumps and well
>pumps that are not easily unplugged.

Use the circuit breaker box to shut off ALL other circuits, and then
time the interval, it takes for the meter disk to make a revolution
while running that appliance.

Their is a calibration constant printed on the meter.. For GE meter's
it's on the face plate in lower right hand corner. My meter has a Kh
7.2 constant..

That's 7.2 Kilowatt hours per 1000 revolutions, or 7.2 watt hours per
single revolution. From that point on, it's simple math..

For real low energy devices, use the calibration markings on the disk.
Measure low long it takes for the disk to turn 1/10 or 1/5 of a
revolution. For high energy usage devices(A/C, hot water, etc),
measure how long it takes to turn 5 or 10 revolutions.

>
>Does anyone know of a device that I could connect (possibly at the breaker
>box) with minimal wiring that would enable me to monitor power use in this
>way?

See above.. Run each appliance independently.. Time the meter before
and after you run it .. calculate wattage difference and place a
little note/label on that device. Make's a handy reminder. If the
numer changes over time, it may be a warning that an appliance may
need servicing.


Tim Keating
ktcn...@mediaone1.net (Note: Remove numeric digits before responding

Peter Bogiatzidis

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Jul 10, 2001, 7:34:26 PM7/10/01
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Hello,

You might also want to take a look at www.wattstopper.com and check out
their PL-100 Plug Load Analyzer. Hope this helps.

Peter.

"Tim Keating" <NotForJ...@mediaone1.net> wrote in message
news:gb7pjt475hub3nm1r...@4ax.com...

Steven Tjiang

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Jul 11, 2001, 8:17:00 AM7/11/01
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Pretty cool.

Any information on prices?

"Leonard Joosten" <ljoo...@engagenet.com> wrote in message
news:3b3a2404$1...@windy.powercom.net...

Leonard Joosten

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Jul 13, 2001, 11:47:29 AM7/13/01
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Pricing on veris is:
H6010 series with LCD $668.83
This also needs 1 CT for a single phase load or 3 CTs for a 3 phase
load.
The CTs run from $130.50ea for a 100 amp to $238.75ea for 2400 anp
H8050 series self-contained kWh pulse output
Single phase is $498.75 for 100 amp to $588.53 for 2400 amp
Three phase is $621.25 for 100 amp to $733.08 for 2400 amp

There is also the networked 8035/8036 series.
You need software to read them.
The 8900 software is $500
All the meters are 3phase. Priced from $673.75 for a 100 amp energy only
meter to $1001.53 for a 2400 amp power quality meter.

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