|
Home > Archive > Alternative Power sources > August 2005 > Household electrical current to Excel ???
You are viewing an archived Text-only version of the thread.
To view this thread in it's original format and/or if you want to reply to
this thread please [click here]
| Author |
Household electrical current to Excel ???
|
|
| Declan McEvoy 2005-08-29, 1:21 pm |
| Hi All,
I want to be able to monitor electrical usage in the home in real time and
to be able to see the effects of for example turning off the TV or turning
on the water heating in graphical or numeric form.
I looking for opinions on the best way(s) and product(s) for doing this.
Presumably one would simply measure the electrical current drawn from the
consumer board and send this reading to the PC using some kind of data
acquisition board and software?
I'm really not all that familiar with the products that are out there for
doing this and would appreciate any help / opinions.
I trolled Deja News and so apologise if it has been aired before!
Declan.
| |
| Palindr☻me 2005-08-29, 1:21 pm |
| Declan McEvoy wrote:
> Hi All,
>
> I want to be able to monitor electrical usage in the home in real time and
> to be able to see the effects of for example turning off the TV or turning
> on the water heating in graphical or numeric form.
>
> I looking for opinions on the best way(s) and product(s) for doing this.
>
> Presumably one would simply measure the electrical current drawn from the
> consumer board and send this reading to the PC using some kind of data
> acquisition board and software?
>
> I'm really not all that familiar with the products that are out there for
> doing this and would appreciate any help / opinions.
>
> I trolled Deja News and so apologise if it has been aired before!
>
You can get a data logger, with a split core sensor, that will sense the
current in your main supply cable and pass the data to a computer and
hence to your spread sheet. It won't be as accurate as the supply meter
but should do for what you want.
http://www.onsetcomp.com/Newsletter...home_power.html
The point of the split core sensor is that it just clips onto the live
but insulated wire from the meter/supply fuse - no having to go near any
bare wires or contacts.
You may think it a bit pricey though.
If you are into electronics, an opto-reflective switch held on the face
of the electricity supplier's consumption meter may do it. Mine did,
just held in place with Blutac and aligned to look at the face of the
rotating meter disk with its black markings. Just feed the output from
it into the parallel port and count the transitions. That was very cheap
- the opto-switch came out of a defunct vcr.
--
Sue
| |
|
|
"Declan McEvoy" <ngacs@eircom.net> wrote in message
news:zIFQe.4634$R5.843@news.indigo.ie...
> Hi All,
>
> I want to be able to monitor electrical usage in the home in real time and
> to be able to see the effects of for example turning off the TV or turning
> on the water heating in graphical or numeric form.
>
> I looking for opinions on the best way(s) and product(s) for doing this.
>
> Presumably one would simply measure the electrical current drawn from the
> consumer board and send this reading to the PC using some kind of data
> acquisition board and software?
>
> I'm really not all that familiar with the products that are out there for
> doing this and would appreciate any help / opinions.
>
> I trolled Deja News and so apologise if it has been aired before!
>
>
> Declan.
Check with the local Eaton Electric office. See if there is anyone that is
savvy into the old IMPACC system. You could get a power/energy sentinel and
connect it up to an old computer.
IMPACC has a special modem that communicates to the devices. Data base is
CSV, right down your alley.
I have several of the setups running at different times for my customers.
I suggest this cause the company is not selling IMPACC anymore. They might
give you a set up. Or know of a company in the neighborhood that upgraded to
the current product. The power/energy sentinels are utility grade,
depending on your rate structure. If your in Kalifornia with low peak, high
peak, mid peak, etc. You need an better product.
E-mon has some simple meters that are good. So does PML
If your going to do it make sure that you keep the accuracy within 2-3% not
much sense in going to all of the trouble and expense for a WAG.
| |
| Paul E. Bennett 2005-08-29, 2:21 pm |
| Palindr?me wrote:
[%X]
> If you are into electronics, an opto-reflective switch held on the face
> of the electricity supplier's consumption meter may do it. Mine did,
> just held in place with Blutac and aligned to look at the face of the
> rotating meter disk with its black markings. Just feed the output from
> it into the parallel port and count the transitions. That was very cheap
> - the opto-switch came out of a defunct vcr.
Not all electricity supply meters have the rotating disk (mine does not). I
haven't yet investigated the flash rate of the LED with varying current
consumption but it may be possible to use that with an opto-sensor over the
LED.
--
********************************************************************
Paul E. Bennett ....................<email://peb@amleth.demon.co.uk>
Forth based HIDECS Consultancy .....<http://www.amleth.demon.co.uk/>
Mob: +44 (0)7811-639972
Tel: +44 (0)1235-811095
Going Forth Safely ....EBA. http://www.electric-boat-association.org.uk/
********************************************************************
| |
| Palindr☻me 2005-08-29, 3:21 pm |
| Paul E. Bennett wrote:
> Palindr?me wrote:
>
> [%X]
>
>
>
>
> Not all electricity supply meters have the rotating disk (mine does not).
Hence the "may" ..
>I
> haven't yet investigated the flash rate of the LED with varying current
> consumption but it may be possible to use that with an opto-sensor over the
> LED.
>
In the UK, ac clamp ammeters are being sold new for around 12GBP. I did
once end up interfacing to the 7 segment displays of one piece of kit as
the only way of getting its reading into a digital control system - so
it *may* be possible to do it that way. I haven't seen a clamp meter
with a built in computer interface, but I guess they exist - probably
well out of my price range.
--
Sue
| |
|
| On Mon, 29 Aug 2005 16:24:00 +0100, Declan McEvoy wrote:
Someone from on Misterhouse list, named Alan Womack, did built
a cheap device that seem to work fine. This was done 2-3 years ago.
look for "power meter" in the archive.
He did mention the following site.
http://www.seanadams.com/pge/
And some post have his personal pictures
> Hi All,
>
> I want to be able to monitor electrical usage in the home in real time and
> to be able to see the effects of for example turning off the TV or turning
> on the water heating in graphical or numeric form.
>
> I looking for opinions on the best way(s) and product(s) for doing this.
>
> Presumably one would simply measure the electrical current drawn from the
> consumer board and send this reading to the PC using some kind of data
> acquisition board and software?
>
> I'm really not all that familiar with the products that are out there for
> doing this and would appreciate any help / opinions.
>
> I trolled Deja News and so apologise if it has been aired before!
>
>
> Declan.
--
----------------------------------------------------------------------
Gaetan Lord - FTA - gaetan@sgi.com - SGI - Montreal, Canada
"I deserve the right to be wrong"
----------------------------------------------------------------------
| |
| Dave Houston 2005-08-29, 4:21 pm |
| Declan,
It would cut down on non-applicable responses if you would note that you're
in Ireland. What voltage do you have there?
"Declan McEvoy" <ngacs@eircom.net> wrote:
>Hi All,
>
>I want to be able to monitor electrical usage in the home in real time and
>to be able to see the effects of for example turning off the TV or turning
>on the water heating in graphical or numeric form.
>
>I looking for opinions on the best way(s) and product(s) for doing this.
>
>Presumably one would simply measure the electrical current drawn from the
>consumer board and send this reading to the PC using some kind of data
>acquisition board and software?
>
>I'm really not all that familiar with the products that are out there for
>doing this and would appreciate any help / opinions.
>
>I trolled Deja News and so apologise if it has been aired before!
>
>
>Declan.
>
| |
| Jerry Avins 2005-08-29, 5:21 pm |
| Paul E. Bennett wrote:
> Palindr?me wrote:
>
> [%X]
>
>
>
>
> Not all electricity supply meters have the rotating disk (mine does not). I
> haven't yet investigated the flash rate of the LED with varying current
> consumption but it may be possible to use that with an opto-sensor over the
> LED.
Current isn't a sure measure of power. Fluorescent and
fractional-horsepower motors consume less power for the same current
than do toasters and incandescent lamps. The results will be useful, but
inexact enough so that like spring scales, they should be considered
"not legal for use in trade."
Jerry
--
Engineering is the art of making what you want from things you can get.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
| |
| Dan Bloomquist 2005-08-29, 5:21 pm |
|
Linny wrote:
> On Mon, 29 Aug 2005 16:24:00 +0100, Declan McEvoy wrote:
>
> Someone from on Misterhouse list, named Alan Womack, did built
> a cheap device that seem to work fine. This was done 2-3 years ago.
> look for "power meter" in the archive.
>
> He did mention the following site.
> http://www.seanadams.com/pge/
>
> And some post have his personal pictures
Nice hack.
But if time is money and you want to capture the signature of motor
start-ups...
Take a couple of cheap current transformers and a door bell transformer
for sensors. (The first one I did was twenty five years ago using a hall
device and multiplying in a MC1495)
These days just take your three outputs and run them to something like
the LabJack.
http://www.labjack.com/labjack_u12.html
Now you can even catch the power factor of reactive loads. At 20 samples
per cycle you won't do to bad. If you are into it, you can hang a
multiport AD converter on the parallel port.
The question, 'does someone have a package ready to go?'. I'm sure there
is. But it is likely to be industrial pricing requiring labview.
Best, Dan.
--
Add one for email
| |
| Dave Houston 2005-08-29, 5:21 pm |
| If you want to roll your own, look at...
http://www.allegromicro.com/hall/currentsensor.asp
Dan Bloomquist <public21@lakeweb.com> wrote:
>
>
>Linny wrote:
>
>
>Nice hack.
>
>But if time is money and you want to capture the signature of motor
>start-ups...
>
>Take a couple of cheap current transformers and a door bell transformer
>for sensors. (The first one I did was twenty five years ago using a hall
>device and multiplying in a MC1495)
>
>These days just take your three outputs and run them to something like
>the LabJack.
>http://www.labjack.com/labjack_u12.html
>
>Now you can even catch the power factor of reactive loads. At 20 samples
>per cycle you won't do to bad. If you are into it, you can hang a
>multiport AD converter on the parallel port.
>
>The question, 'does someone have a package ready to go?'. I'm sure there
>is. But it is likely to be industrial pricing requiring labview.
>
>Best, Dan.
| |
| Dennis Mchenney 2005-08-29, 5:21 pm |
| For LOW cost try here. You will need to have a main and branch cicuit
sensor inputs of some type and > $ 100 each for LOW resolution is the
norm. Log data to *.cvs FORMATED file and open in Excell maybe.
http://www.labjack.com/index.html
Declan McEvoy wrote:
> Hi All,
>
> I want to be able to monitor electrical usage in the home in real time and
> to be able to see the effects of for example turning off the TV or turning
> on the water heating in graphical or numeric form.
>
> I looking for opinions on the best way(s) and product(s) for doing this.
>
> Presumably one would simply measure the electrical current drawn from the
> consumer board and send this reading to the PC using some kind of data
> acquisition board and software?
>
> I'm really not all that familiar with the products that are out there for
> doing this and would appreciate any help / opinions.
>
> I trolled Deja News and so apologise if it has been aired before!
>
>
> Declan.
>
>
| |
| Palindr☻me 2005-08-29, 5:21 pm |
| Dennis Mchenney wrote:
> For LOW cost try here. You will need to have a main and branch cicuit
> sensor inputs of some type and > $ 100 each for LOW resolution is the
> norm. Log data to *.cvs FORMATED file and open in Excell maybe.
>
> http://www.labjack.com/index.html
I think that this one may be a bit cheaper:
http://www.quasarelectronics.com/3093.htm
--
Sue
| |
| daestrom 2005-08-29, 6:21 pm |
|
"Jerry Avins" <jya@ieee.org> wrote in message
news:dMadnThmoeiZ_I7eRVn-sQ@rcn.net...
> Paul E. Bennett wrote:
>
> Current isn't a sure measure of power. Fluorescent and
> fractional-horsepower motors consume less power for the same current than
> do toasters and incandescent lamps. The results will be useful, but
> inexact enough so that like spring scales, they should be considered "not
> legal for use in trade."
>
I think his point is that his *kwh* meter doesn't use a rotating disk. Nor
does mine. Mine has an LCD readout of the kwh used, and a small 'dot' that
pulses on/off as energy is drawn through the unit. I'll bet that his LED is
actually registering watt-hours, not just 'current'.
Connecting an optical sensor to a flashing LED would be easier than sensing
my meter's LCD 'dot' though. For mine, I would need some light source and a
focused sensor to detect reflection. :-(
daestrom
| |
| daestrom 2005-08-29, 6:21 pm |
|
"Dennis Mchenney" <mchenney@mindspring.com> wrote in message
news:43135BCE.4010705@mindspring.com...
> For LOW cost try here. You will need to have a main and branch cicuit
> sensor inputs of some type and > $ 100 each for LOW resolution is the
> norm. Log data to *.cvs FORMATED file and open in Excell maybe.
>
> http://www.labjack.com/index.html
>
If you're handy with the signal conditioning, you can get *really* cheap
A/D->PC by using iButtons and related 'one-wire' devices from Dallas
Semiconductor.
http://www.maxim-ic.com/1-Wire.cfm
I use some of their temperature sensors to monitor my domestic hot-water
heat-exchanger, hot-air furnace, and the temperatures in my attic.
daestrom
P.S. It helps if you can do a little programming as their software
development kit is a bit 'stone-knife and bearskin'
| |
| Pete C. 2005-08-29, 8:21 pm |
| daestrom wrote:
>
> "Jerry Avins" <jya@ieee.org> wrote in message
> news:dMadnThmoeiZ_I7eRVn-sQ@rcn.net...
>
> I think his point is that his *kwh* meter doesn't use a rotating disk. Nor
> does mine. Mine has an LCD readout of the kwh used, and a small 'dot' that
> pulses on/off as energy is drawn through the unit. I'll bet that his LED is
> actually registering watt-hours, not just 'current'.
>
> Connecting an optical sensor to a flashing LED would be easier than sensing
> my meter's LCD 'dot' though. For mine, I would need some light source and a
> focused sensor to detect reflection. :-(
>
> daestrom
The last time I looked closely at one of the "digital" utility meters in
a commercial installation (only place I've seen them used) it still had
the good ol' spinning disk, although it was buried inside the unit and
not visible on the front.
I've seen some pretty cheap multimeters that have RS232 ports, I think
RS carries one, but I've seen them in the $20-$30 range other places.
Add a decent clamp on amp probe to one of these meters and you have
pretty cheap data acquisition. I think the ones I've seen claim to be
true RMS as well which will greatly help your accuracy with the odd
power factor loads.
Pete C.
| |
| Solar Flare 2005-08-29, 9:21 pm |
| Look at the Kh or Kp spec on the nameplate. Some newer ones are 1.0 whr per
flash. Some do not flash at all unless you swipe a magnet across the bottom
somewhere to activate the technician mode.
"Paul E. Bennett" <peb@amleth.demon.co.uk> wrote in message
news:devcqd$912$1$830fa17d@news.demon.co.uk...
> Palindr?me wrote:
>
> [%X]
>
>
> Not all electricity supply meters have the rotating disk (mine does not).
I
> haven't yet investigated the flash rate of the LED with varying current
> consumption but it may be possible to use that with an opto-sensor over
the
> LED.
>
> --
> ********************************************************************
> Paul E. Bennett ....................<email://peb@amleth.demon.co.uk>
> Forth based HIDECS Consultancy .....<http://www.amleth.demon.co.uk/>
> Mob: +44 (0)7811-639972
> Tel: +44 (0)1235-811095
> Going Forth Safely ....EBA. http://www.electric-boat-association.org.uk/
> ********************************************************************
| |
| Solar Flare 2005-08-29, 9:21 pm |
| The flashing LCD spot is usually a place to calibrate the meter to in the
service shop. Look for a stated kp, Kh, Ki, Ke or other designation on the
front nameplate. Some of them are now 1 kwh per flash.
for a disk meters the power measured = revs x Kh x 3600 / Tsec.
clock a few revs or flashes (about a minutes worth) and multiply it out for
a very accurate power mesurement
Most 200A mechanical meters have a Kh = 7.2 or 12.0
Most 100A mechanical meters have a Kh = 3.6 or 6.0
"daestrom" <daestrom@NO_SPAM_HEREtwcny.rr.com> wrote in message
news:UgKQe.51580$Hx4.41740@twister.nyroc.rr.com...
>
> "Jerry Avins" <jya@ieee.org> wrote in message
> news:dMadnThmoeiZ_I7eRVn-sQ@rcn.net...
cheap[color=darkred]
not).[color=darkred]
current[color=darkred]
than[color=darkred]
"not[color=darkred]
>
> I think his point is that his *kwh* meter doesn't use a rotating disk.
Nor
> does mine. Mine has an LCD readout of the kwh used, and a small 'dot'
that
> pulses on/off as energy is drawn through the unit. I'll bet that his LED
is
> actually registering watt-hours, not just 'current'.
>
> Connecting an optical sensor to a flashing LED would be easier than
sensing
> my meter's LCD 'dot' though. For mine, I would need some light source and
a
> focused sensor to detect reflection. :-(
>
> daestrom
>
>
| |
|
|
| Dan Bloomquist 2005-08-30, 1:21 am |
|
daestrom wrote:
> "Dennis Mchenney" <mchenney@mindspring.com> wrote in message
> news:43135BCE.4010705@mindspring.com...
>
>
> If you're handy with the signal conditioning, you can get *really* cheap
> A/D->PC by using iButtons and related 'one-wire' devices from Dallas
> Semiconductor.
> http://www.maxim-ic.com/1-Wire.cfm
>
> I use some of their temperature sensors to monitor my domestic hot-water
> heat-exchanger, hot-air furnace, and the temperatures in my attic.
>
> daestrom
> P.S. It helps if you can do a little programming as their software
> development kit is a bit 'stone-knife and bearskin'
Thanks daestrom,
I hadn't noticed this maxim line well enough. Interesting enough to keep
me busy for a while. Digi-key sells their stuff. Did you start with the
DS9090K? (Why pound your thumb with a hammer for a lack of $65?  I
haven't seriously had a soldering iron in my hand for a few years, I
miss it...
I like it so far.
Best, Dan.
--
Add one for email
| |
| Palindr☻me 2005-08-30, 4:21 am |
| Dennis Mchenney wrote:
> The U12 USB is only $99 US, the more expensive first listed has Ethernet.
>
> http://www.labjack.com/labjack_u12.html
Sorry, I looked at their UK distributor prices, as the OP appeared to be
in Ireland, it would be nearest.. By the time taxes and shipping was
added, the 99 USD had turned into >110GBP..I am not sure what it would
have cost shipped direct from the USA - everytime I have got things like
the the Customs people have added 25% duty on, and then the post office
added another chunk for collecting it..I could really do with a chum in
the USA who would forward things for me.
Quasar, the same company as I mentioned, do have PC data acquisition
analogue units from ~18 GBP, on the same website. I have used many of
their kits for all sorts of things, so am happy to recommend them.
[color=darkred]
>
> Palindr☻me wrote:
>
| |
| Declan McEvoy 2005-08-30, 6:21 am |
| Lots of good info to digest here. Yes I am in Ireland and should have
pointed out that we use 220 Volts @ 50 Hz.
Declan.
"Dave Houston" <nobody@whocares.com> wrote in message
news:431359c0.18036348@nntp.fuse.net...
> Declan,
>
> It would cut down on non-applicable responses if you would note that
you're
> in Ireland. What voltage do you have there?
>
....Snip..........
| |
| Declan McEvoy 2005-08-30, 7:21 am |
| That data logger and current clamp looks good. I wonder can it pass the info
directly to Excel without having to gather and store the collected data. I
wonder what the approx cost of the logger and clamp is?
The problem (I think) with the second option, the optical sensor is that it
takes a long time for one rev of the disk if there is only minimal things
happening in the house and so the responsivness of seeing the effects of
turning on and off appliances for short periods (10 secs) might not be good
or immediate.
Declan
"Palindr?me" <sb382638@hotmail.com.invalid> wrote in message
news:11h6b85ndb3eg28@corp.supernews.com...
> You can get a data logger, with a split core sensor, that will sense the
> current in your main supply cable and pass the data to a computer and
> hence to your spread sheet. It won't be as accurate as the supply meter
> but should do for what you want.
>
> http://www.onsetcomp.com/Newsletter...home_power.html
>
> The point of the split core sensor is that it just clips onto the live
> but insulated wire from the meter/supply fuse - no having to go near any
> bare wires or contacts.
>
> You may think it a bit pricey though.
>
> If you are into electronics, an opto-reflective switch held on the face
> of the electricity supplier's consumption meter may do it. Mine did,
> just held in place with Blutac and aligned to look at the face of the
> rotating meter disk with its black markings. Just feed the output from
> it into the parallel port and count the transitions. That was very cheap
> - the opto-switch came out of a defunct vcr.
>
>
> --
>
> Sue
>
| |
| Palindr☻me 2005-08-30, 7:21 am |
| Declan McEvoy wrote:
> That data logger and current clamp looks good. I wonder can it pass the info
> directly to Excel without having to gather and store the collected data. I
> wonder what the approx cost of the logger and clamp is?
>
> The problem (I think) with the second option, the optical sensor is that it
> takes a long time for one rev of the disk if there is only minimal things
> happening in the house and so the responsivness of seeing the effects of
> turning on and off appliances for short periods (10 secs) might not be good
> or immediate.
As other posters have pointed out - some meters do not have disks at
all! Mine has a regular pattern of black radial bars near the edge,
giving 100 divisions. Yours may easily be different. An opto-sensor*
looking at the bars of mine is certainly capable of resolving an
increase of say 50W in total load for 10 seconds duration. *Human eye,
that is - using an electronic opto-sensor would give far better
resolution, as the time between bars could be resolved to microseconds,
if need be.
--
Sue
| |
| Dave Houston 2005-08-30, 10:21 am |
| With the proliferation of switch mode power supplies and other non-linear
loads, you need a much higher sampling rate.
Dan Bloomquist <public21@lakeweb.com> wrote:
>But if time is money and you want to capture the signature of motor
>start-ups...
>
>Take a couple of cheap current transformers and a door bell transformer
>for sensors. (The first one I did was twenty five years ago using a hall
>device and multiplying in a MC1495)
>
>These days just take your three outputs and run them to something like
>the LabJack.
>http://www.labjack.com/labjack_u12.html
>
>Now you can even catch the power factor of reactive loads. At 20 samples
>per cycle you won't do to bad. If you are into it, you can hang a
>multiport AD converter on the parallel port.
>
>The question, 'does someone have a package ready to go?'. I'm sure there
>is. But it is likely to be industrial pricing requiring labview.
>
>Best, Dan.
| |
| Duncan McNiven 2005-08-30, 2:21 pm |
| On Tue, 30 Aug 2005 09:44:59 +0100, "Declan McEvoy" <ngacs@eircom.net>
wrote:
>Lots of good info to digest here. Yes I am in Ireland and should have
>pointed out that we use 220 Volts @ 50 Hz.
Here is a UK source for a multi-meter with an RS-232 port and data
logging software:
http://www.greenweld.co.uk/acatalog/New_Items.html
The price (£96) is rather more than the similar items seen by Pete C
though.
--
Duncan
| |
| Palindr☻me 2005-08-30, 2:21 pm |
| Duncan McNiven wrote:
> On Tue, 30 Aug 2005 09:44:59 +0100, "Declan McEvoy" <ngacs@eircom.net>
> wrote:
>
>
>
>
> Here is a UK source for a multi-meter with an RS-232 port and data
> logging software:
> http://www.greenweld.co.uk/acatalog/New_Items.html
> The price (£96) is rather more than the similar items seen by Pete C
> though.
>
Here is one for 29.99GBP - although you may have to wait for it to
arrive in stock. They have others at under 50GBP.
http://www.maplin.co.uk/Module.aspx...=46381&doy=30m8
The software is pretty rudimentary, but you can just log it into
hyperterm and then cut and paste it into Excel..
--
Sue
| |
| Derek Broughton 2005-08-30, 2:21 pm |
| > Dan Bloomquist <public21@lakeweb.com> wrote:[color=darkred]
>
All these solutions that I have seen require you to have your computer
plugged into the monitor. Since I'm off-grid, my specific aim is to
monitor usage for the least amount of power consumed in the monitoring
process - even plugging in the old laptop to do it just doesn't cut it.
Anybody seen anything like the labjack that can store captured data and
download it on demand?
--
derek
| |
| Palindr☻me 2005-08-30, 2:21 pm |
| Derek Broughton wrote:
>
>
> All these solutions that I have seen require you to have your computer
> plugged into the monitor. Since I'm off-grid, my specific aim is to
> monitor usage for the least amount of power consumed in the monitoring
> process - even plugging in the old laptop to do it just doesn't cut it.
> Anybody seen anything like the labjack that can store captured data and
> download it on demand?
The various websites posted include autonomous data loggers as well as
pc-dependent ones. It will, of course, still need power and almost
certainly have a processor, firmware and memory. A bit like an "old
laptop", in fact...
My laptop runs for days of use off an external small sealed lead acid
battery.. which I just throw in the car and recharge when I go anywhere.
--
Sue
| |
| Dan Bloomquist 2005-08-30, 3:21 pm |
|
Dave Houston wrote:
> With the proliferation of switch mode power supplies and other non-linear
> loads, you need a much higher sampling rate.
You can low pass the sensors, i.e., integrate the window. Both the
current transformers and the voltage transformer have a low output
impedance, so the delays will match up.
Best, Dan.
--
Add one for email
| |
| Duncan McNiven 2005-08-30, 3:21 pm |
| On Tue, 30 Aug 2005 17:54:06 +0100, Palindr?me
<sb382638@hotmail.com.invalid> wrote:
>Here is one for 29.99GBP
Much more attractive price!
>The software is pretty rudimentary, but you can just log it into
>hyperterm and then cut and paste it into Excel..
Have you tried it? Does it pump out readings periodically or on
demand? Is the protocol documented so you can write your own software?
--
Duncan
| |
| Palindr☻me 2005-08-30, 4:21 pm |
| Duncan McNiven wrote:
> On Tue, 30 Aug 2005 17:54:06 +0100, Palindr?me
> <sb382638@hotmail.com.invalid> wrote:
>
>
>
>
> Much more attractive price!
>
>
>
>
> Have you tried it? Does it pump out readings periodically or on
> demand? Is the protocol documented so you can write your own software?
>
You can pose those questions on the maplin web site. One of the ones I
have free runs and samples every second and outputs a fixed baudrate
ASCII string after each data capture. Others output in response to a
single character input. If you set terminal echo on, /some/ models of
the latter will take one of the echo characters as the trigger and just
keep doing conversion after conversion. It doesn't seem to matter that
it is getting many trigger characters that it doesn't use. I can't
promise that this little klduge will always work though.
Thus the protocol is very, very simple and it would be a doddle to write
your own software - assuming that you /can/ write software, that is!
There are public domain libriaries/dll for Windows that make it easy to
set up and utilise a serial port - although development envirnments like
Delphi often already have them.
--
Sue
| |
| Dave Houston 2005-08-30, 6:21 pm |
| Dan Bloomquist <public21@lakeweb.com> wrote:
>Dave Houston wrote:
>
>You can low pass the sensors, i.e., integrate the window. Both the
>current transformers and the voltage transformer have a low output
>impedance, so the delays will match up.
It's not just a matter of phase but of non-sinusoidal wave shapes. You must
sample frequently to get an accurate picture.
| |
| daestrom 2005-08-30, 6:21 pm |
|
"Solar Flare" <sflare@hotmail.com> wrote in message
news:OK2dnaU7rMMpP47eRVn-tA@golden.net...
> The flashing LCD spot is usually a place to calibrate the meter to in the
> service shop. Look for a stated kp, Kh, Ki, Ke or other designation on
> the
> front nameplate. Some of them are now 1 kwh per flash.
>
> for a disk meters the power measured = revs x Kh x 3600 / Tsec.
>
> clock a few revs or flashes (about a minutes worth) and multiply it out
> for
> a very accurate power mesurement
>
> Most 200A mechanical meters have a Kh = 7.2 or 12.0
> Most 100A mechanical meters have a Kh = 3.6 or 6.0
>
Yeah, I know all that. Kh similar to the old revolving disk type. But the
initial problem is how to electronically sense the 'flashing' LCD 'spot'.
Can't open the meter up and backlight it. Such a tiny 'spot' (less than
1/8" diameter) is hard to focus on with any sort of reflection optics.
Doesn't 'glow' on its own at night.
daestrom
| |
| daestrom 2005-08-30, 6:21 pm |
|
"Pete C." <aux3.DOH.4@snet.net> wrote in message
news:43139041.288A6822@snet.net...
<snip>
>
> The last time I looked closely at one of the "digital" utility meters in
> a commercial installation (only place I've seen them used) it still had
> the good ol' spinning disk, although it was buried inside the unit and
> not visible on the front.
>
National Grid went through the service area and replaced all the old
revolving disk KWH meters 'en mass'. In fact you can buy an old one cheap
from the company that picked them up. Supposedly reduced the number of
meter-readers by a large percentage. The new ones are RF read. The meter
reader just drives down the street slowly in his truck, and all the meters
respond to his transducer with a serial no. and kwh reading. Electronically
recorded, downloaded to the corporate mainframe and spits out the monthly
bill.
The gas meters now have an attachement that goes in the spot where the
original dials were ('extension dials' that can still be read by homeowner),
and are also RF.
Supposedly this model is also capable of other 'neat things', like TOU, but
they haven't put that in the tariff yet.
> I've seen some pretty cheap multimeters that have RS232 ports, I think
> RS carries one, but I've seen them in the $20-$30 range other places.
> Add a decent clamp on amp probe to one of these meters and you have
> pretty cheap data acquisition. I think the ones I've seen claim to be
> true RMS as well which will greatly help your accuracy with the odd
> power factor loads.
>
Well, 'true RMS' will help out with measuring current when the waveform is
distorted. As it is for some electronics like PC power supplies and CFL.
But unless you can measure the phase displacement between voltage and
current, you *still* won't have a good power reading for things like A/C,
refrigerators and other motor-driven items.
daestrom
| |
| daestrom 2005-08-30, 7:21 pm |
|
"Dan Bloomquist" <public21@lakeweb.com> wrote in message
news:9EQQe.1291$Xo3.1182@news01.roc.ny...
>
>
> daestrom wrote:
>
>
> Thanks daestrom,
> I hadn't noticed this maxim line well enough. Interesting enough to keep
> me busy for a while. Digi-key sells their stuff. Did you start with the
> DS9090K? (Why pound your thumb with a hammer for a lack of $65? I
> haven't seriously had a soldering iron in my hand for a few years, I miss
> it...
>
> I like it so far.
The one thing I ran into, is a lot of their products are surface mount.
But I was able to 'SuperGlue' a 1/8 dowel underneath the 8 pin package and
then solder some hairline strands to the legs. Ran the strands to some more
conventional 22AWG, and wrapped the whole thing up in a layer of tape.
Gives me a nice 'probe' about 3/16" diameter that I can poke into furnace
ducts, strap onto hot-water pipe (with some foam pipe insulation around
probe to help improve accuracy) or whereever. Even drilled small hole in
sill-plate and stuck one through to get an 'outdoor' reading.
Although two of the units failed early because of my... (ahem...) soldering
skill with SO packages (well, afterall I was using a 15w pencil iron to do
SO, so what can you expect). But once I got things down pat, I've gotten 12
working units.
Had some old cat-5 scraps, and there was already a couple of cat-5 runs up
to the attic area. Made for good wire to connect them all together. So now
I have a linux box sitting in the basement 'logging' temperatures from all
around the attic, basement, furnace.
Got some of their straight A/D converters from another hobby source. These
came with the surface mount chip already mounted in a standard 8-pin dip
plug. They only take 0-5V input, so I've been tinkering with some 'signal
conditioner' circuits to attach a solar cell for measuring potential 'sun
input' for different placements around the place.
Just a hobby, but interesting, keeps me off the streets. And my wife
doesn't mind as long as there's no wires strung across the kitchen table ;-)
daestrom
| |
| Palindr☻me 2005-08-30, 7:21 pm |
| daestrom wrote:
> "Dan Bloomquist" <public21@lakeweb.com> wrote in message
> news:9EQQe.1291$Xo3.1182@news01.roc.ny...
>
>
>
> The one thing I ran into, is a lot of their products are surface mount.
>
> But I was able to 'SuperGlue' a 1/8 dowel underneath the 8 pin package and
> then solder some hairline strands to the legs. Ran the strands to some more
> conventional 22AWG, and wrapped the whole thing up in a layer of tape.
> Gives me a nice 'probe' about 3/16" diameter that I can poke into furnace
> ducts, strap onto hot-water pipe (with some foam pipe insulation around
> probe to help improve accuracy) or whereever. Even drilled small hole in
> sill-plate and stuck one through to get an 'outdoor' reading.
>
> Although two of the units failed early because of my... (ahem...) soldering
> skill with SO packages (well, afterall I was using a 15w pencil iron to do
> SO, so what can you expect). But once I got things down pat, I've gotten 12
> working units.
>
> Had some old cat-5 scraps, and there was already a couple of cat-5 runs up
> to the attic area. Made for good wire to connect them all together. So now
> I have a linux box sitting in the basement 'logging' temperatures from all
> around the attic, basement, furnace.
>
> Got some of their straight A/D converters from another hobby source. These
> came with the surface mount chip already mounted in a standard 8-pin dip
> plug. They only take 0-5V input, so I've been tinkering with some 'signal
> conditioner' circuits to attach a solar cell for measuring potential 'sun
> input' for different placements around the place.
>
> Just a hobby, but interesting, keeps me off the streets. And my wife
> doesn't mind as long as there's no wires strung across the kitchen table ;-)
You might be quite interested by this:
http://www.quasarelectronics.com/3145.htm
Which is what I have used for a similar reason to yours!
By fitting the sensor into a standard utp connector, wired to some of
the "spare" cores, you can just plug them in where you fancy, moving
them when you want, and connect out at the patch panel.
--
Sue
| |
| Derek Broughton 2005-08-30, 8:21 pm |
| Palindr?me wrote:
> The various websites posted include autonomous data loggers as well as
> pc-dependent ones.
Oh well, I _thought_ I'd followed all the links... I'll check again.
> It will, of course, still need power and almost
> certainly have a processor, firmware and memory. A bit like an "old
> laptop", in fact...
Not really. I'd seriously considered trying to work something up with the
"old Palm m100". My old laptop was only a consideration because (a) I
don't use it, and (b) it has barely enough memory to handle this chore.
The Palm actually has as much memory, and vastly lower power consumption.
However, I doubt I'd find any off-the-shelf equipment for a Palm, so it
would end up being a hardware project and I'm a software guy...
A data logger that stored a day or a week of data, and then let me download
it at my convenience would be much nicer.
> My laptop runs for days of use off an external small sealed lead acid
> battery.. which I just throw in the car and recharge when I go anywhere.
I _could_ run it off the DC power at my inverter, too, but that's not the
point. I'm trying to avoid using anything that power hungry.
--
derek
| |
| Palindr☻me 2005-08-30, 9:21 pm |
| Derek Broughton wrote:
> Palindr?me wrote:
>
>
>
>
> Oh well, I _thought_ I'd followed all the links... I'll check again.
Here'ssome:
http://www.onsetcomp.com/Products/P.../H08family.html
If you want more, I'll find some - but it is hlf past midnight and Sue
*really* needs her beauty sleep..
| |
| Anthony Matonak 2005-08-30, 9:21 pm |
| daestrom wrote:
....
> Yeah, I know all that. Kh similar to the old revolving disk type. But the
> initial problem is how to electronically sense the 'flashing' LCD 'spot'.
> Can't open the meter up and backlight it. Such a tiny 'spot' (less than
> 1/8" diameter) is hard to focus on with any sort of reflection optics.
> Doesn't 'glow' on its own at night.
Perhaps an optical proximity sensor might work. They usually use
an LED paired with a detector. Alternatively, a laser pointer
might be used to illuminate the spot.
Anthony
| |
| Solar Flare 2005-08-30, 9:21 pm |
| We have reflective scanner type pickups for calibration checking.
Sometimes there is an IR LED tht flashes also. Sometimes the units do not
flash except in "test" mode. This ca be accomplished by triggering a reed
switch at the bottom of the meter or bottom left side on some units. Some
have to have combo of buttons pressed inside with the glass off now.
What is the meter type?
"daestrom" <daestrom@NO_SPAM_HEREtwcny.rr.com> wrote in message
news:AU3Re.53147$Hx4.40303@twister.nyroc.rr.com...
>
> "Solar Flare" <sflare@hotmail.com> wrote in message
> news:OK2dnaU7rMMpP47eRVn-tA@golden.net...
the[color=darkred]
>
> Yeah, I know all that. Kh similar to the old revolving disk type. But
the
> initial problem is how to electronically sense the 'flashing' LCD 'spot'.
> Can't open the meter up and backlight it. Such a tiny 'spot' (less than
> 1/8" diameter) is hard to focus on with any sort of reflection optics.
> Doesn't 'glow' on its own at night.
>
> daestrom
>
>
| |
| Solar Flare 2005-08-30, 9:21 pm |
| In Ontario you have the right to demand a pulse output from a Commercial
style meter. I doubt ths applies to a residential type though.
"daestrom" <daestrom@NO_SPAM_HEREtwcny.rr.com> wrote in message
news:AU3Re.53147$Hx4.40303@twister.nyroc.rr.com...
>
> "Solar Flare" <sflare@hotmail.com> wrote in message
> news:OK2dnaU7rMMpP47eRVn-tA@golden.net...
the[color=darkred]
>
> Yeah, I know all that. Kh similar to the old revolving disk type. But
the
> initial problem is how to electronically sense the 'flashing' LCD 'spot'.
> Can't open the meter up and backlight it. Such a tiny 'spot' (less than
> 1/8" diameter) is hard to focus on with any sort of reflection optics.
> Doesn't 'glow' on its own at night.
>
> daestrom
>
>
| |
| Dennis Mchenney 2005-08-31, 12:21 am |
| Cheap PCB's including SMT
http://www.expresspcb.com/
daestrom wrote:
> "Dan Bloomquist" <public21@lakeweb.com> wrote in message
> news:9EQQe.1291$Xo3.1182@news01.roc.ny...
>
>
>
> The one thing I ran into, is a lot of their products are surface mount.
>
> But I was able to 'SuperGlue' a 1/8 dowel underneath the 8 pin package and
> then solder some hairline strands to the legs. Ran the strands to some more
> conventional 22AWG, and wrapped the whole thing up in a layer of tape.
> Gives me a nice 'probe' about 3/16" diameter that I can poke into furnace
> ducts, strap onto hot-water pipe (with some foam pipe insulation around
> probe to help improve accuracy) or whereever. Even drilled small hole in
> sill-plate and stuck one through to get an 'outdoor' reading.
>
> Although two of the units failed early because of my... (ahem...) soldering
> skill with SO packages (well, afterall I was using a 15w pencil iron to do
> SO, so what can you expect). But once I got things down pat, I've gotten 12
> working units.
>
> Had some old cat-5 scraps, and there was already a couple of cat-5 runs up
> to the attic area. Made for good wire to connect them all together. So now
> I have a linux box sitting in the basement 'logging' temperatures from all
> around the attic, basement, furnace.
>
> Got some of their straight A/D converters from another hobby source. These
> came with the surface mount chip already mounted in a standard 8-pin dip
> plug. They only take 0-5V input, so I've been tinkering with some 'signal
> conditioner' circuits to attach a solar cell for measuring potential 'sun
> input' for different placements around the place.
>
> Just a hobby, but interesting, keeps me off the streets. And my wife
> doesn't mind as long as there's no wires strung across the kitchen table ;-)
>
> daestrom
>
>
| |
| Dennis Mchenney 2005-08-31, 1:21 am |
| Cheap PCB's including SMT
http://www.expresspcb.com/
daestrom wrote:
> "Dan Bloomquist" <public21@lakeweb.com> wrote in message
> news:9EQQe.1291$Xo3.1182@news01.roc.ny...
>
>
>
> The one thing I ran into, is a lot of their products are surface mount.
>
> But I was able to 'SuperGlue' a 1/8 dowel underneath the 8 pin package and
> then solder some hairline strands to the legs. Ran the strands to some more
> conventional 22AWG, and wrapped the whole thing up in a layer of tape.
> Gives me a nice 'probe' about 3/16" diameter that I can poke into furnace
> ducts, strap onto hot-water pipe (with some foam pipe insulation around
> probe to help improve accuracy) or whereever. Even drilled small hole in
> sill-plate and stuck one through to get an 'outdoor' reading.
>
> Although two of the units failed early because of my... (ahem...) soldering
> skill with SO packages (well, afterall I was using a 15w pencil iron to do
> SO, so what can you expect). But once I got things down pat, I've gotten 12
> working units.
>
> Had some old cat-5 scraps, and there was already a couple of cat-5 runs up
> to the attic area. Made for good wire to connect them all together. So now
> I have a linux box sitting in the basement 'logging' temperatures from all
> around the attic, basement, furnace.
>
> Got some of their straight A/D converters from another hobby source. These
> came with the surface mount chip already mounted in a standard 8-pin dip
> plug. They only take 0-5V input, so I've been tinkering with some 'signal
> conditioner' circuits to attach a solar cell for measuring potential 'sun
> input' for different placements around the place.
>
> Just a hobby, but interesting, keeps me off the streets. And my wife
> doesn't mind as long as there's no wires strung across the kitchen table ;-)
>
> daestrom
>
>
| |
| Scott Seidman 2005-08-31, 10:21 am |
| "daestrom" <daestrom@NO_SPAM_HEREtwcny.rr.com> wrote in news:Oi4Re.53387
$Hx4.26919@twister.nyroc.rr.com:
> The one thing I ran into, is a lot of their products are surface mount.
There are a variety of products that break SMT products into something
easier to prototype. One produce is at http://www.elexp.com/pro_sbrd.htm
--
Scott
Reverse name to reply
| |
| Pete C. 2005-08-31, 10:21 am |
| daestrom wrote:
>
> "Pete C." <aux3.DOH.4@snet.net> wrote in message
> news:43139041.288A6822@snet.net...
> <snip>
>
> National Grid went through the service area and replaced all the old
> revolving disk KWH meters 'en mass'. In fact you can buy an old one cheap
> from the company that picked them up. Supposedly reduced the number of
> meter-readers by a large percentage. The new ones are RF read. The meter
> reader just drives down the street slowly in his truck, and all the meters
> respond to his transducer with a serial no. and kwh reading. Electronically
> recorded, downloaded to the corporate mainframe and spits out the monthly
> bill.
I've seen the RF read meters, but the ones I saw were definitely still
the spinning disk at their core. Looked like they simply printed an
encoder track on the surface of the disk and point an optical sensor
block at it.
Certainly reduced reading errors too. In the year or so before they
deployed the RF meters I twice had to call in updated readings when the
reader goofed on an upper digit. Probably didn't notice numerous errors
on lower digits since the change would of course be smaller. Fortunately
the error isn't cumulative since the next accurate reading corrects the
error.
I did find one small fault with the RF meters though, on a service that
was not in use. The encoder was apparently right at the edge of the
reading and on the second month read 1 kwh less than the previous
reading. You'd think that their computer would flag a service that
suddenly showed like a 9,999 kwh reading, but the bozos sent a $15k
bill. The CSR did get quite a laugh when I pointed it out.
>
> The gas meters now have an attachement that goes in the spot where the
> original dials were ('extension dials' that can still be read by homeowner),
> and are also RF.
>
> Supposedly this model is also capable of other 'neat things', like TOU, but
> they haven't put that in the tariff yet.
I think the fancy meters with the LCD displays have the TOU capability,
but what I saw deployed in CT appeared to be essentially a normal disk
meter with an encoder and RF transponder. Much cheaper than the full
blown meter I'm sure.
>
>
> Well, 'true RMS' will help out with measuring current when the waveform is
> distorted. As it is for some electronics like PC power supplies and CFL.
> But unless you can measure the phase displacement between voltage and
> current, you *still* won't have a good power reading for things like A/C,
> refrigerators and other motor-driven items.
Well, achieving measuring perfection on a budget isn't easy. If you can
get good true RMS readings to the PC for $60 that isn't bad.
Pete C.
| |
|
| If you have access to surplus Radio Frequency meters of the type used
on broadcast stations ( transmitter's site) and you can break your
power line to insert a meter, open the meter's case and attach a
couple of wires to the internal meter connections, after the
thermocouple.
The meter will display the r.m.s. current and will give you a dc
connection to the outside
Connect the 2 wires to a voltmeter with a serial output and you can
display all the information you need and/or use excel for further
manipulation.
Those meters are very precise and usually available from surplus
places.
Advantages are that they measure r.m.s current, disadvantages are that
they are very sensitive to overload. You apply twice the maximum
current and the thermocouple is finished.
Vlad
On Mon, 29 Aug 2005 16:24:00 +0100, "Declan McEvoy" <ngacs@eircom.net>
wrote:
>Hi All,
>
>I want to be able to monitor electrical usage in the home in real time and
>to be able to see the effects of for example turning off the TV or turning
>on the water heating in graphical or numeric form.
>
>I looking for opinions on the best way(s) and product(s) for doing this.
>
>Presumably one would simply measure the electrical current drawn from the
>consumer board and send this reading to the PC using some kind of data
>acquisition board and software?
>
>I'm really not all that familiar with the products that are out there for
>doing this and would appreciate any help / opinions.
>
>I trolled Deja News and so apologise if it has been aired before!
>
>
>Declan.
>
| |
|
| On Wed, 31 Aug 2005 11:30:16 -0400, Vlad <Bla@dot.com> wrote:
>If you have access to surplus Radio Frequency meters of the type used
>on broadcast stations ( transmitter's site) and you can break your
>power line to insert a meter, open the meter's case and attach a
>couple of wires to the internal meter connections, after the
>thermocouple.
>The meter will display the r.m.s. current and will give you a dc
>connection to the outside
>Connect the 2 wires to a voltmeter with a serial output and you can
>display all the information you need and/or use excel for further
>manipulation.
>
>Those meters are very precise and usually available from surplus
>places.
>
>Advantages are that they measure r.m.s current, disadvantages are that
>they are very sensitive to overload. You apply twice the maximum
>current and the thermocouple is finished.
>
>Vlad
Let me clarify some thing.
The meters are very precise because the scale is printed to conform to
the actual current. The dc output will not be linear . You may use
excel to give you the same reading as the meter's scale.
Vlad
[color=darkred]
>
>On Mon, 29 Aug 2005 16:24:00 +0100, "Declan McEvoy" <ngacs@eircom.net>
>wrote:
>
| |
| daestrom 2005-08-31, 7:21 pm |
|
"Pete C." <aux3.DOH.4@snet.net> wrote in message
news:4315ABF4.A674D80B@snet.net...
> daestrom wrote:
>
> I've seen the RF read meters, but the ones I saw were definitely still
> the spinning disk at their core. Looked like they simply printed an
> encoder track on the surface of the disk and point an optical sensor
> block at it.
>
That's a bit like the rig National Grid uses for the *gas* meters around
here. But the kwh meters *couldn't have a disc in them anymore. The new
ones are much 'flatter' to the meter box. Unless they turned the disk
vertical to fit it inside behind the electronic display?
This is CA's certification for the same exact style meter as we have here.
http://www.cdfa.ca.gov/dms/CTEP%20A...004/5403-04.pdf
We have the Schlumberger CENTRON, "CL 200 240V 3W TYPE C1SR 3.0TA 1.0Kh".
Of course the 1.0Kh means 1 watt-hour per 'revolution'. But the one on my
house is like the one described in the link as the 'non-segment check'
version. The little square pulses on for 1 watt-hour, then off for the next
watt-hour, and so on.
> Certainly reduced reading errors too. In the year or so before they
> deployed the RF meters I twice had to call in updated readings when the
> reader goofed on an upper digit. Probably didn't notice numerous errors
> on lower digits since the change would of course be smaller. Fortunately
> the error isn't cumulative since the next accurate reading corrects the
> error.
>
> I did find one small fault with the RF meters though, on a service that
> was not in use. The encoder was apparently right at the edge of the
> reading and on the second month read 1 kwh less than the previous
> reading. You'd think that their computer would flag a service that
> suddenly showed like a 9,999 kwh reading, but the bozos sent a $15k
> bill. The CSR did get quite a laugh when I pointed it out.
>
Surprising. When I was working a web project for a utility in the midwest
(getting ready for deregulation and making customer info available on-line),
we were explicitly tasked to check for just such things. Meter readings
shouldn't go 'backward' from one month to the next, unless it spanned the
'rollover' range.
daestrom
| |
| daestrom 2005-08-31, 7:21 pm |
|
"Solar Flare" <sflare@hotmail.com> wrote in message
news:L6WdnXhk_a80aYneRVn-jw@golden.net...
> We have reflective scanner type pickups for calibration checking.
>
> Sometimes there is an IR LED tht flashes also. Sometimes the units do not
> flash except in "test" mode. This ca be accomplished by triggering a reed
> switch at the bottom of the meter or bottom left side on some units. Some
> have to have combo of buttons pressed inside with the glass off now.
>
> What is the meter type?
>
Schlumberger CENTRON
"CL 200 240V 3W Type C1SR 30TA 1.0Kh"
This is a CA cert. summary for the meter.
http://www.cdfa.ca.gov/dms/CTEP%20A...004/5403-04.pdf
Mine is the 'non-segment check' style, much like the photograph on the left.
daestrom
| |
| Solar Flare 2005-08-31, 9:21 pm |
| We didn't get involved with that particular type. I will see what I can find
out from the meter guys about it. I jumped departments a few years ago and
have lost touch with it a bit.
Pretty small spot!!
"daestrom" <daestrom@NO_SPAM_HEREtwcny.rr.com> wrote in message
news:9%pRe.48506$EX.46581@twister.nyroc.rr.com...
>
> "Solar Flare" <sflare@hotmail.com> wrote in message
> news:L6WdnXhk_a80aYneRVn-jw@golden.net...
not[color=darkred]
reed[color=darkred]
Some[color=darkred]
>
> Schlumberger CENTRON
> "CL 200 240V 3W Type C1SR 30TA 1.0Kh"
>
> This is a CA cert. summary for the meter.
> http://www.cdfa.ca.gov/dms/CTEP%20A...004/5403-04.pdf
>
> Mine is the 'non-segment check' style, much like the photograph on the
left.
>
> daestrom
>
>
|
|
|
|
|