Greening Your Home - Listening in on your electric meter?

http://www.itron.com/pages/products_detail.asp?id=itr_000240.xml&pf=e
I looked up my C1SR electric meter on the web (Itron meters), and it seems to be transmitting my power usage on the 900 mHz band.
(So the meter reader doesn't need to get out of his car).

So, since this is a built-in whole-house power usage meter, has anyone ever made a DIY monitor to get a real time power reading?(So I don't need to try and interpret flashing dots).

It seems like this would be almost as good as owning a T.E.D unit.. :)
http://www.theenergydetective.com/what/overview.html

Very interesting, but that site doesn't go into details at all. (I didn't go as far as searching other sites.) All they basically say is that the meter can use any number of AMR technologies, like a drop-in-type deal, so yours isn't necessarily using the 900MHz band at all. I'm assuming you haven't listened to it yet.

What leads you to believe it is broadcasting your instantaneous usage? I didn't see that anywhere on the site. All it really needs to send it the meter serial number and the total kwh reading. Better than having to go out in the cold and jot down a number but no more precise. Precision-wise I think you'd be much better off watching flashing lights than trying to time how long it takes to burn through a whole kwh.

Of course you'll need a radio with a descriminator tap. A rat shack PRO-95 scanner is easily modified. But at ~$100 you're quickly approaching the cost of a TED. (And yes, I have one of those too and love it!)

It's certainly an interesting project but if I just wanted to know my power usage and didn't care about learning how the transmissions work I'd just shell out the $150 rather than investing in radio equipment and more importantly all the time required to decipher the protocol.

I saw a few things that described the 900 mHz band and also frequency hopping. (Which might be the death knell for the idea).

I think those meters might be sending out the current readings down to the 0.1KWH (or maybe better).
If so, and the transmit burst-repeat rate was pretty fast, one may be able to capture and plot the real-time usage..

I've already got a radio (IC-R8500) that can be computer controlled to step around the 900 mHz band, but so far, I've seen nothing that tells me anything about the type of modulation or the protocol.

I've not even pulled out the radio, since I just did a quick survey done with a 0.1 to 1.5 Ghz bug-finder didn't show anything at 900.
If it's a fast Spread Spectrum transmitter, it just might look like noise to my gear.. :(
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So, you like the TED.. Are you using a PC hookup?
I've read there are problems with the software.

If I got one, I'm not sure that I would even need the
PC hookup, since it does provide a realtime LCD diplay
of about everything that I want to know.

Yes, I too saw some things that described the 900MHz band, but my point is the manufacturer has made their meter in such a way that they can use whatever freq and protocol they want.

You simply don't know where they are right now. And in fact they may not even have an AMR plugin in there at all. Your meter could be a normal one with no transmission plugin.

A "bug finder"? This sounds like cheap gear. Maybe it's not, and I apologize in advance. But I would certainly use a frequency counter. But even then you will not pick up the burst when you're scanning such a LARGE range. Problem here is it transmits for such a short time.

Can your computer translate the data bursts at the end of your public safety transmissions? That's much easier, which is why I ask.

-core

P.S. Nope I'm not using a PC hookup. The thing is _amazing_ as it is.

Not to poke fun, but writing a video camera interface to "read" the display would be infinitely easier than anything else. Just a thought.

is a StarTek counter, model 15-BG and it does have pretty good sensitivity on the bar graph display.
Just putting the antenna near an RF source (inside the freq range) will show up on the bar graph, without the need to 'lock on' to the signal.
IIRC, some 900 mHz phones wouldn't lock up (with an extact freq), but could easily be seen on the bar graph.

All the docs I've seen point towards 900 mHz. Since it's an FCC 'open' band, the meter makers seem to really like it.
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Anyways, I sure like the idea of buying a TED. But, I'm wondering what it's sensitivity is.?.
What is the minimum load that could come on line and be seen by the TED?

TIA,

I'm wondering what it's sensitivity is.?.
What is the minimum load that could come on line and be seen by the TED?

I must say that's a strange question considering what the TED is! (Whole house meter?)

Can I ask what exactly you need to know? I can move my pickup leads to a single circuit with a very small load to test, since my panel is still open.

Anyway I'll try to answer anyway without knowing: The TED only indicates in increments of 10W. Who knows why, but that's what it does. It's the only thing I don't like about it.

And yes, I have every reason to believe it indicates 10W if the actual usage is 6W or whatever. Although admittedly I haven't gotten it down that far yet. I have a "phantom" load in my house of about 30W that I haven't yet tracked down, and it measured that, and so did my disc meter.

From my tests the disc is reading about 10-15% higher than the TED. The TED does have calibration on it to compensate for this but I'm not gonna do that until I get the power company out here to explain their greedy calibration. And no, I have not cross-referenced the readings with a known load... yet. On my list of things to do.


So.... guess I'm not sure what you're asking. If you're expecting to see 16W vs. 7W, ain't gonna happen. But just about any other 'normal' circumstance, sure you'll see it right there on the screen.

What I really like is the instantaneous nature of it. It does average over a second or so, but that's still much better than a stopwatch out at the meter.

For example: I can sit here and watch the induced draft fan on my furnace kick on (100W), then the hot surface ignitor glow (900), then finally the main blower (450) come on. All in the course of 50 seconds. Try that with a stopwatch!

At a glance I know if my refrigerator compressor is on. Or if anything else is on that I may or may not know about. I love the thing.

In fact it probably saved my house just a few weeks ago. I saw something intermittently using 1200W briefly every 8 seconds. Checked everything and couldn't find the source. Turns out the sitter had turned on a malfunctioning burner on the cooktop and left it on. With all the stuff I throw on my stove I'm quite convinced I would have had a fire if it weren't for this little TED.

All the complex stuff it does with the power tiers is cool but I have no use for it, myself. I just want to know how many watts I'm burning. But definitely for someone who wants to see a dollar amount on a realtime basis it would be great.

Really, can't say enough about the thing. I love it. Mostly I'm just glad I'm not out in the snow with a stopwatch anymore. ;)

Well, 10 watts of resolution isn't too bad.
About what I expected of a unit that will likely display up to 15 or 20KW.

Moving the clips around to find hidden loads seems like too much trouble, when I could just watch the LCD and open breakers one at a time. :thinker:

Anyways, I'm sold. I do like the simplicity of the gadget and now I need to sell my wife on the idea..

If I was you, I would make sure all the 'HOT' indicators on those cooking elements are working and stop leaving things where they could get cooked.. :madhell:

You got me thinking about the times our iron was left plugged in, down in the basement!:coffee:

Thanks for the good info. If I get a TED, I'll be back to pick your brain..