Estimating KWh electicity billing using clamp-on amp meter

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Seems a bit extreme. That says that the power company would need not only a key to the meter box, but also a key to the business to get inside anytime they want. A situation that would seem to expose them to all kinds of potential security issues.
It also doesn't say that YOU cannot have a key as well.
Regardless of what is happening in other places, many of them in other countries as outlined below, have you asked the electric company if you can have a key?

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snipped-for-privacy@optonline.net wrote:

Hi, Often saw in my working days, meter inside a box but it always had an opening(window) so one can see the reading and so on.
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harry wrote:

(I note that no explicit answer is given for that question)

So are you saying that customers with "demand meters" are billed on the basis of their peak demand - a reading based on only a few minutes worth of energy usage as seen over an entire billing period?
How is that a fair or equitable way to bill a customer?
Are commercial customers that typically use between 2000 and 3000 kwh of electricity per month normally considered as candidates for a demand meter, or are they used for much higher usage customers?
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On 5/29/2011 8:59 AM, Home Guy wrote:

No. It's immaterial to the usage; only determines what the appropriate rate will be. Again, that only will matter if you're actually on a demand-based billing (which, personally, I would doubt for a small office-type complex, but wouldn't be impossible).
...

Yes
What's "fair" got to do with it? :)
It's owing to the fact that as another already posted, facilities have to be provided by the utility to handle the peak load; that costs more so they bill more. It's also an incentive to the customer to look at load-leveling techniques aggressively to cut their costs.

Generally, much higher.
All you'll have to do is look at your bill and you'll know what the tariff schedule is.
Again, you're looking in the wrong place here, first.
In all likelihood, the "problem" is _NOT_ in the metering but in either having an unknown or parasitic load, the "reading" not being actual reading but estimated until the "catch up" real reading at the beginning of the year or other explainable issue. The likelihood of your meter being in error is quite low for the explanation of the usage data you previously posted.
--
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I wouldn't say it that way. It's very material in that (as you clarify) it sets the rate for the usage. Just nit-picking to make it clear to the OP that there are two very clearly different factors to consider in business rates that are different from residential rates. A power blip that ended up turning every device on simultaneously (a rare situation - except for X-10 users <g>) could be an extremely costly event. Why? Because peak demand rates are set by the maximum power ever used during the metering period. The OP could have easily changed the dynamics of his billing by plugging in a couple of new space heaters at exactly the wrong time. That sort of event could easily explain why the OP finds himself owing a lot more money than last year even though the kWh used could be virtually identical.

I've learned (the very hard way) that with posters here from all over the world, many of the things I thought were customary nation or world-wide are just local quirks. (-:

"Deserves got nothing to do with it" - Unforgiven

No, I beg to differ. I always feel much more comfortable encountering service personnel and such knowing as much as I can learn elsewhere. I believe the OP has learned a great deal from this thread and could get to the point where an encounter isn't even necessary. His bill probably holds the sad tale of a one time excursion into a higher rate zone that's cost him big time. I'll bet he now becomes very aggressive managing his peak load.
I would suggest dropping $25 for a basic Kil-O-Wat plug in meter
http://www.newegg.com/Product/Product.aspx?Item=N82E16882715001
to measure the current draw of all his equipment. Then I'd figure out some sort of switching interlock or timer system to insure that loads don't all coincide.

Which is why I recommend the Kil-O-Watt meter. You can measure each device (except hard-wired ones) and get a true reading (wattage or V/A) of its instantaneous power consumption or the consumption over a period of time. A clamp meter is a good way to measure the items hardwired to the circuit panel, but it's pretty lousy for determining wattage or power consumption over time for stand-alone devices.
- Bobby G.
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On 5/29/2011 10:03 PM, Robert Green wrote: ...

...
I get no feeling OP has really learned a thing...it seems to all just pass over as it doesn't fit into the preconceived notion.
His complaint is he has a few months w/ very high usage; not that the $ amount is high at relatively low total usage (as would be the symptom of a demand-induced premium). I think the likelihood he actually has a demand meter is very low.
From the numbers on usage he posted before, it appears to be a fairly consistent usage w/ a couple of months extreme outliers. Both of those are early in different years; my hypothesis is that the other months are, for the most part, estimated rather than actually read and the one annual blip is the catchup because they've not updated the average usage to reflect actual since it was set up (probably before OP bought the building).
--
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Smitty Two wrote:

What a joke.
The "power coming into the building" can be no more than the power being used by the building's equipment, devices or appliances.
That fact that I've got some high-rated switch gear and primary supply wire shouldn't play a role in how I'm billed. It's still a basic 3-phase 120/208 supply. Nothing fancy.
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Home Guy wrote:

Hi, Is that 3-ph. Delta or Star configured? So many were talking about Pf and still you talk like that? I resigned, over and out. It may be easier to tech my cat.
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wrote:

It is wye connected. If it were delta it would be 120/240.
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to
holds
him
load.
I'd be reluctant to say that. Once a thread gets to a certain level of "tension" it becomes more a question of Quien es mas Macho?

Checking what I have for the beginning of the thread (and my newserver gets swamped when those Teranewsians' server fails <g>) he started, at least, asking three specific questions:
1) when coming up with a total current measurement, do I include the current flowing on the neutral line?
2) He was looking how to calculate the "worst case" (all loads operating simultaneously I assume)
3) He wanted to know if there was an error in how he intended to calculate a maximum load.
That's at least why I recommended the Kil-O-Watt. He described a large number of easily tested, non-hardwired loads on his premises.
I do see in reviewing the thread from top down that his 1st line reply to RBM was:
"RBM used improper usenet message composition style by full-quoting:"
Maybe that's his newsreader automatically set to net-nanny "FULL ON" (-: So maybe you're right, the OP has a bit to learn about not biting the hand that's feeding him and was contributory in this interesting thread turning slightly sour. My mistake.

Because I've had my own tangles with bad meters and something the phone company called a "left on" connection (that actually turned into a national security matter), I pay attention to news reports of billing errors. This could just as easily be a screw-up with his electric company's billing systems. They are forever futzing with their programs to account for new "revenue streams" and fees and could have made any number of mistakes. Based on the level of errors I've seen reported in DoD studies, shift happens. A decimal point here and there, the wrong variable name, etc.
While you may be perfectly correct in why the readings show the way they do, there are a lot of other explanations. But it terms of learning, I think we (and perhaps he) have learned some critical things. You can't meter the neutral of a three-phase feeder and expect to get information about total usage, only the level of imbalance of the downstream circuits. We've learned that it's unusual not to be able to see your meter whenever you choose to, but apparently not universal. That's something for the OP to work out between himself, the power company and his landlord. As nearly everyone has said, to solve the puzzle more information is needed.
But I don't think it could ever hurt him to spend $25 on a Kil-O-Watt meter. He indicated from the start he wanted to measure total wattage, and the KOW will do that far better for the gear he has than any tong meter I know of. It calculates true wattage and can measure average usage over long periods of time. Going to the power company to investigate further knowing *exactly* what he's got in his office will let them know that he's done his homework, at least. That's important in dealing with them.
-- Bobby G.
"When the universe comes to destroy man, man will still be nobler than that which tries to destroy him, because in his death man knows he is dying and of its victory, the universe knows absolutely nothing." - Pascal
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On 6/1/2011 5:47 AM, Robert Green wrote:
...

...
Indeed it could...

...
I never said (and hopefully didn't imply by poor wording) my idea was the only possible explanation; simply a theory (apparently refuted, eventually).
OP is the (new, but not terribly so iirc 6yr) owner of the building so I'd presume he has some pull w/ the landlord... :) It would seem anything about the lock on the cabinet/meter that he would be allowed to do by whatever limitations placed by the utility/city could have been resolved in that time. If the limitation is only inertia on his part, that's another kettle...there's insufficient information to know _why_ it is currently as it is.
It's a commercial building w/ 3-phase service and the loads he mentioned were a few computers, basically. The Kil-O-Watt meter can monitor them but it'll do nothing for what is most likely by far the majority of the load which will be the 3-phase lighting, possibly water heater and other service loads. It'll be measuring the noise around the edges.
The characteristics of the peculiarities aren't likely to be explained by a loading issue anyway imo. The doubling of the readings in months that are roughly a year apart is just not credible as an ordinary event of somebody left the lights on over a weekend. It's either an accounting issue, an error in the reading or the like that is artificially being induced somewhat like your above suggestion (or mine of a different yet similar mechanism) or there's a _major_ intermittent load or fault somewhere on the system.
Either of those isn't going to be found by a minimal one-time guesstimate of the maximum possible monthly usage even if he measures an instantaneous 3-phase usage correctly and it certainly won't be found by poking around on one computer supply at a time.
$0.02, imo, ymmv, etc., etc., etc., ...
--
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On 6/1/2011 5:47 AM, Robert Green wrote: ...

...
I did intend to indicate and give credit that he did recognize he needed the full 3-phase usage only that it seemed as though had hard time coping with what he proposed is too rudimentary to help much (or at all) in resolving his problem...in that even if he knew the answer he proposed it doesn't get anywhere at the root cause of the symptom.
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Agreed. He's gonna have to call the power company, like it or not. At this point he at least needs their interpretation of the bill. Then he can either accept it or refute their explanation but at least he would have a better understanding of what's (allegedly) going on.
-- Bobby G.
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wrote:
Or the OP could have an an electrician install an emon demon like RBM suggested in his main service panel and the reading from it and the amount of electricity the OP is being billed for should always agree...
http://www.emon.com/index.html
~~ Evan
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Or the OP could have an an electrician install an emon demon like RBM suggested in his main service panel and the reading from it and the amount of electricity the OP is being billed for should always agree...
http://www.emon.com/index.html
~~ Evan ---------------------------------------------------------------------------- ------- That's true, but it will cost a bunch of money. The Kil-O-Watt is dirt cheap, it's an essential tool that EVERYONE who cares about the co$t of electricity should have, AND it doubles-checks the company meter using a wholly different way of computing usage than the company uses and even the sub-meter at emon uses.
If their meter is bad or wired to a parasitic load, remotely monitoring a sub-meter won't help a bit. It seems everyone here is making a lot of assumptions based on facts not entered into evidence. If he does an inventory with the KOW and the aggregate demand of each electrical device doesn't come within a ballpark figure of the company billing, THEN he's got some work to do. The KOW won't catch problems like running the A/C and the heat at the same time (I had that experience at one job site where the server room was independently cooled at the same time it was centrally heated and the power bills skyrocketed).
The remote monitor might not catch an idiot neighbor who has vampire tapped the OP's circuits. How do you catch a 20A circuit "accidentally" going to the space next door with a sub-meter any better than you can with the main meter? How can a sub-meter or remote monitor solution catch an electric resistance heater in someone else's space that he's paying for? That's a hell of a lot more common than people might think in multiple occupant dwellings. The original occupants know they have some cross-linked wiring but deal with it in their lease or informally. When they move out, the institutional memory of how that cross-linking worked goes with them.
I lived for a little while with an A/C unit in MY closet that served the tenant on the other side of the divided up second floor. I took the cover off the A-coil and cooled my little studio apartment quite nicely by keeping a fan pointed at the coil. I was a broke college student at the time and felt that if I had to deal with the noise of the unit, I should get some compensation. I moved out a week later when I heard something under the bed and looked to see a roach as large as a mouse scuttle slowly across the floor. When your actually hear a roach's footfalls, you know it's time to trot b'wana. But that's another story . . .
The point is that someone could be doing something nasty like that to the OP. The cabinet might be locked by a tampered looking to keep his tampering away from prying eyes. (-:
In any event, I honestly believe that for the OP's peace of mind, as well as getting some real data points about consumption independent of the meter, spending $25 is a no-brainer. Doing an electrical inventory seems to be a better idea than hiring an electrician to install something he might not ever need if he determines the bill is accurate. I'm in favor of everyone doing a Kil-O-Watt type inventory of their home because they would be surprised to find what some of the high-tech toys take in electricity just to keep the IR remote control or some other circuitry alive.
FWIW, what do you think the cost of an emon d-mon would be for a business? I couldn't find any prices on their site which makes me nervous. It's a technique that typically mean "high priced." I've got a similar system built around a home automation controller that cost about $250 total. Assuming this system needs the same kind of electronics and add another $250 for the install and you're talking $500! I suspect our solutions differ in cost by at least a factor of 20. That's a lot in a cost-centric world.
If HomeGuy was an SOB, he could even send the meter back because saying "It loses its kWh readings if the unit is unplugged or the power blinks." That's the cheap model's Achilles' heel. The more expensive units have a battery and many other features. *IF* he was a skunk and sent it back after using it, that would put the cost at less than $10. But HomeGuy doesn't sound like a skunk, just a perplexed business owner trying to control his costs. He's not an electro-techie yet he's somehow pissed off a whole lot of electro-techies who seem to believe he should be "getting it" by now.
This thread in particular was really a lot less collegiate than it should have been. People "get it" when they "get it" and insulting them doesn't ever help them "get it" faster, it usually just degenerates the thread. It has to make you wonder if that's not the goal: Not to be helpful, but to deliberately *try* to start an on-line brawl. I guess it's spring and the testosterone's running higher than the mighty Mississippi.
Home Guy, I'll probably take a beating myself for saying this (fish got to swim, scolds have to scold) but I'm sorry you took such a pounding. It's uncalled for, especially over an apolitical issue like this. If you really want to take a beating, try starting this thread. "I want to design a system to limit my kid's PC and phone use." The scolds will be clawing each other bloody trying to explain that you wouldn't need such a system if you were a better parent. They will probably even insult your kids whom they've never met nor know anything about. That's Usenet!
It always takes two to tango but abusing someone because they don't understand something in a group that's allegedly here to share information seems a bit harsh. It never makes anyone understand any better, it just raises their hackles. Can anyone here ever remember a *competent* teacher dealing with a student that way? Of course not. So why is it OK here to question someone's intelligence repeatedly on what is a complex techno-geographical question whose true parameters are probably still not known to a majority of posters and are peculiar to the OP's location? Everyone went to DefCon 4 in a microsecond. It usually takes this sort of

their horns a little?
Who hasn't gotten a utility bill and thought "Gee, that seems a bit high?" The Kil-o-Watt is the cheapest, safest way to get a roadmap of your power consumption and to find out what watthogs need to be tamed. It's a must unless you like paying money to the electric company that could have stayed in your pocket.
-- Bobby G.
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On 5/30/2011 4:51 AM, Robert Green wrote: ...

Again, this ignores the symptom as posted earlier--over 17 months the average is reasonably consistent w/ two extreme outliers (which are both early in separate calendar years).
If the meter were faulty that wouldn't be the kind of error on would expect; one would expect continuously high (or may getting higher) usage indication if it's over-metering. Or, the parasitic/stolen load is intermittent. Or some other effect nobody's thought of.
Yet again, I conjecture the "normal" readings are estimated and the large ones are an annual "cactchup" to match reality when the meter is actually physically read again. Certainly not conclusive but there's bound to be a reason and it's unlikely the OPs simplistic technique is going to get anywhere in resolving the issue.
As others have said, a physical photocopy of a couple of the monthly bills (obviously w/ personal data elided) posted at a hosting site would be quite an interesting exhibit.
A monitoring of what can be will start, but in a complex he'll still have quite a few loads that can't be on the kill-o-watt meter (sp?); as far as I know they're only available for single-phase loads and his main loads likely are the lights/heat/etc that I would presume are 3...
There seems a fixation on this demand meter but a) don't even know if it is, and b) even if were, doesn't make any difference other than $$ amounts; doesn't explain/have anything to do w/ the above usage data that aren't the billing amounts but the used kwh.
--
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dpb wrote:

I've stated already that the meter is consistently read by a person on either the first or second business day of the month. This person must be escorted to the utility room where the meter is located. About half the time I do this, and when I don't to it a co-worker does, and I'm told about it.
Our water meter is read by the same person at the same time.
Since never a single month goes by without a reading, your theory of estimated billing caused by a missed reading should not apply.
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On 5/30/2011 8:57 AM, Home Guy wrote:

Well, that's first time I've seen it stated that you personally knew the meter was physically read; previously left the possibility/probability that the reader did his thing w/o your personal knowledge; only you presumed it was done.
Do you verify the readings this person takes at the time? Since there's such a question when the large reading shows up, it would seem only reasonable to do so.
I can then only go back to the suggestion of ask, ask, ask, for what is going on. Somehow, something is very different in those particular months (but I don't think it's the meter itself that is likely the cause).
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I've never heard of a power company that would give a crap about the water meter. Is this the same utility? Very unusual in my experience, but anything is possible.
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On 5/30/2011 12:04 PM, Ed Pawlowski wrote:

This is likely a contract meter-reading service I'd guess given that. Altho I've not seen that before, either, seems at least plausible.
Wasn't able to determine who the utility supplier is from previous postings--I thought he said was in CT; the link to the pdf on the rates was a Niagara Mohawk pub though who afaik, are limited to NY. So, can't see whether there is a combined utility in the area or not unless HG tells us.
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