Make a coil with ten turns of the wire to multiply the meter's sensitivity by 10. Make a coil with 100 turns of the wire to multiply the meter's sensitivity by 100.
Or buy a new meter.
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Download the manual:
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-- You can\'t have a sense of humor, if you have no sense!
I think this is the right solution, but buying a new meter just to calibrate the meters in the powermeter boards, seems a waste. Especially since I *have* an accurate meter - the power meter on the side of the house.
Not if it isn't in a usable range.
-- You can\'t have a sense of humor, if you have no sense!
Don't use clamp meters, they often aren't terribly accurate anyhow. Place a shunt, hang a regular good meter that has AC amps to that, say a prayer, don safety goggles and turn the circuit back on.
Mine doesn't own it. Just like the valet service at the fancy restaurant just parks a car yet doesn't assume ownership.
Hmm, that job is done by a wee Samba box here. Smaller than my bible, uses around 10W of power. Also gets turned off every night but you wouldn't have to.
Yikes! Ok, my LAN box won't be able to hold that much. Maybe time to clean that up a bit :-)
Seriously, I did that recently. Just like in a garage there is an amazing volume of stuff one really doesn't need to hang onto anymore.
If the computers have that much of a job then it's tough. Maybe you can concentrate this to just one machine. But yeah, I have also let PCs runs during night hours when executing huge SPICE simulations. I don't know if Linux has a routine to turn a PC to hibernate after the last job has finished.
Watch the prices there. AFAICT propane is not very cost competitive. It does pack more punch so heating a depleted water heater is zippier. But we have occasionally had to pay well north of $4/gallon, more than for gasoline even though propane packs 10% less BTU per gallon.
And you put the pump 480ft down? Looks like you really prepared for super dry conditions.
On clock speed? That somehow doesn't sound right.
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It goes around once every 10-60 seconds, I can scale that easily, either by counting multiple revolutions (if it's fast) or using the
0-100 marks on the edge (if it's slow). I don't need to be *that* accurate ;-)
The water *source* is 430 feet down, at 7.5 gal/min. The pump, when the water level is that far down, can pump 7 gal/min so it will never run dry (it might if the pump were higher, or if it could pump more). But if you let the well fill up, the pump can pump 12 gal/min. There's about 700 gallons of water stored in the well, which lets us
*use* more than 7.5 gal/min for a long time (a few hours), as long as we allow time for the well to fill back up again, but if we don't let it fill up, we'll still get at least 7 gal/min.Every 1/N clocks, it samples the ADCs, multiplies the values, and adds that to the energy accumulator. That's pretty much all it does, plus the calibration stuff. If you put a faster crystal on it, it samples more often, and the accumulated values run higher.
So, the chip focuses on being precise, not accurate. It's up to the user to calibrate it to make it accurate.
This should obviously be "Every N clocks" or "At 1/N the clock rate".
Propane is even worse than that. Gasoline is about 118KBTU/gallon. Propane is closer to 91KBTU/gallon. Heating oil is about
132KBTU/gallon.
Mine is all digital. It is on the far side of the driveway, and out in the hot Florida sun or pouring rain. It is over 100 feet from the nearest workbench.
-- You can\'t have a sense of humor, if you have no sense!
Ah, mine is the old analog one with the aluminum disk.
Progress Energy has replaced every watt-hour meter they own in Florida with digital. It can be read electronically, and supposedly can't give wrong data that happened when the old meters were read by humans. You may not have a mechanical meter much longer, as more companies convert to digital.
-- You can\'t have a sense of humor, if you have no sense!
Mine doesn't have the counter-rotating arrow dials, which cause most of the mis-reads. Mine has an odometer-style display so the number's obvious.
That's what we had when we bought the house. The sun pelted it for many years and then it died. Guess what PG&E replaced it with? Right, a truly retro but brand new Landis&Gyr rotating disk meter, with a multitude of rotating arrows just like you see them in some 1940's movies.
The reason one utility engineer mentioned: Those don't break.
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Sometimes its the bean counters who decide to put up with failed meters, when they can cut overall labor costs.
-- You can\'t have a sense of humor, if you have no sense!
As I guessed, I had the scale factor wrong. Well, I had the right factor, but I assigned it to the wrong channel.
See, it turns out that the values I chose for the load resistors and AC voltage references give me a counter value that's close to "watt-seconds" (it was a coincidence, really). With a little calibration, I can make it *be* "watt-seconds". However, that only works with 120v 20a circuits (1012 turns). For 240v circuits, I need to double the reading. For the other sensors, I need to scale by 2x or 3x (2011 or 3100 turns, with tweaks to the calibration). However, aside from calibration, the chips can only scale *down*, not *up*. So the MCU running the show has a "scale factor" for each channel, and it just multiplies the value read by that constant. Between the scale factor (1, 3, 4, 6, etc) and the gain calibration (-50%..+50%) I can get all the channels to report "watt-seconds" for their given sensors and configuration.
However, I put the '6' in channel 0 (unused) intead of channel 1 (dryer). The dryer actually draws about 5200 watts when it runs, which makes a lot more sense.
I just finished the calibration, and it turns out I wasn't too far off otherwise. We'll see what the data tells us over time. Even if it's off by a fixed percent, as long as each channel is close, the
*relative* costs can be scaled to match the electric bill at the end of the first whole month monitored.
This is the business model for a company I worked for in 1989. SFAIK, meter readers are still cheaper than the electronics & backhaul in AMR systems.
AMR systems are making progress, just slowly.
-- Les Cargill
During a discussion about smart grid style auto-read meters I once got the responses that "it can happen that a utility will respond that Mr.So-and-so does not like it when the measure will cost jobs". I pretty much ended my involvement in that work group ...
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Whoops ...
5200 watts? That's one hell of a fast dryer :-)
True, all you need to do is identify the heavy hitters. And I think you already did, the computers. I know it's painful but that is where the lion's share of your savings potential is located. Since you are a Linux guru it should be a breeze to configure all that so things turn themselves off or into hibernate mode after reaching idle state. I even do that with my tiny file server. The file server needs about two minutes to come back on in the morning, easily bridged by 3-4 sips of coffee and reading the business section of our paper which their budget situation has caused to shrivel down to two pages.
Heck, I even let the big HD in my desktop spool down. It's back up in under 5sec and fully automatic, a small price to pay. We also turn off things like the DSL modem at night. A lot of people have wondered how we stay well under 1000kWh, considering my office and that the pool pumps must run several hours per day.
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It dries twice the clothes in 2/3 the time as our old one :-)
But I can't say that's the average draw for that, I just turned it on for a moment to measure it. It might be that it uses a lower heat setting during parts of the cycle. The logs will show the power profile for it, once we've used it for real, but it was saying ~850 watts before and now it's 6x that, which is about right.
Well, it's a matter of identifying the circuits with the highest
*average* use over time, then figuring out which of those can be reduced, and by how much, and how much the upgrades will cost. Replacing our inefficient fridge is a bad idea, because the payoff is longer than the expected life of the new fridge. Replacing light bulbs makes sense if you know which light bulbs are on most often. Etc.The plan is to let the logs accumulate for a month or two, so we have a whole billing period in logs, and compare that bill (probably October's) to the logs and see how it all works out.
Perhaps. If I can automate the power savings, and make good choices about upgrades, yes. It could easily turn into a money pit though.
Make sure it has a 100% secure and clean vent. That thing could set the house on fire.
I wish we'd all go back to ye olde clothes line. But even my wife doesn't really like that because clothes can dirty up out there on the line and they are fluffier when from the dryer. Whatever the heck fluffy might mean, but once you are married you learn not to questions those things ...
Yep. conservation efforts where investments are required usually only make sense with heavy hitters. Heater, A/C, insulation, pumps, computers.
Actually I invested nothing. The turn-off features came with the equipment. Even the soldering station has a shut-off. Somehow it magically detects when not in use for more than xx minutes.
The only real investments were very small. Two dozen or so energy saver bulbs, floodlights, and such.
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