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
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...
>...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
"Patrick Keith-Hynes" <p...@together.net> wrote in message
news:BROS6.123$N35....@nntp1.onemain.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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>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
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...
Any information on prices?
"Leonard Joosten" <ljoo...@engagenet.com> wrote in message
news:3b3a2404$1...@windy.powercom.net...
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.