Estimating KWh electicity billing using clamp-on amp meter

[dpb]

Even simpler: Rate commissions and consumer advocate groups combined w/ environmental and other regulations...

(30+yr commercial utility engineering experience)

[trader4]

Good, that confirms what I thought. Just wanted to make sure I wasn't missing something.

[Metspitzer]

It is wye connected. If it were delta it would be 120/240.

[Ed Pawlowski]

"Home Guy" wrote

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.

[Evan]

@Home Guy:

Just because you are only using 2,000 kWh a month in your building is meaningless... Your building is equipped with service entrance equipment which could supply it with far more power if you were doing things that needed it...

You clearly do not possess enough information or knowledge to be of any use describing what service equipment you have installed in your building... You say you are only using 120/208 3-phase power, well you have no idea what your building is being supplied with, it could have a 400-amp 277/480 3-phase supply which would mean that you are only using one or two sub panels fed by an on premises transformer...

It is *NOT* the power companies' fault that your building's electrical facilities are GROSSLY over sized for the current occupancy that you are using it for... But that is nothing the power company nor the PUC will ever worry about -- as long as your building is equipped with the service entrance equipment which has 400-amp capacity you will never be able to get rid of the "demand meter" even if your actual power usage is very low at approximately 2,000 kWh a month...

If it is _that_ important to you to no longer have a "demand meter" then you can hire an electrician to remove the old electrical service equipment and install a smaller service in-line with what your actual power consumption is, but until you have all the old power panels and service head removed from your building, the power company WILL NOT install a non-demand meter for your building...

You can ask RBM how much that would cost, depending on the sq. ft. of the building it can be expensive...

~~ Evan

[Evan]

@Home Guy:

Get a clue, 100-amp is *NOT* the smallest installable utility service... It is for houses and buildings but it is not the smallest size of electrical service available...

Traffic signal boxes generally have a 30-amp service and there are pole mounted equipment cabinets for cable companies that also have small services in the way of 30-amp/40-amp single phase...

~~ Evan

[dpb]

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.

[krw]

Our water and electricity (and garbage, and soon to be cable/Internet) are all from the same "company". The city. ;-) ...though the water is billed separately (electricity and garbage are billed together).

[krw]

With a three-phase energy meter, of course, else you would have three meters.

The simple sum of the power in the three phases.

[krw]

You have all this time to fine one counterexample and none to INVESTIGATE YOUR OWN DAMNED BILL? What a complete moron!

[krw]

Whey don't they do peak and off-peak billing? That seems to make more sense and would be easier for the customers to adjust their consumption around,

[dpb]

On 5/30/2011 1:34 PM, [e-mail] wrote: ...

For residential, sure...this is commercial meter, though, not residential even though it is light commercial where it wouldn't make any significant difference in the (apparent) current use as given by OP.

OTOH, for "real" industrial large loads which is really the target, they generally use control algorithms to try to maintain as near level consumption as possible as well as maximize power factor. They do this by phased starting/stopping schedules for the really large gear, etc., etc., etc., as much as is feasible within other operational constraints...

One paper mill for which I did consulting had a very sophisticated startup sequence that relied on precise timing of motor-starting along the >1 mile length of the line. It took something otoo 45 minutes from the initial button press before the last set of rollers began to turn.

Another that used similar logic but that I never actually worked on was the rolling mill making Al can stock at the Alcoa facility in Alcoa, TN. It was a tower facility that had large feed rolls at one end and can stock collected on rollers at the other with about a half-mile of material going up and down in between in successive stages of the rolling process. I always thought it kinda kewl to watch the linear velocity increase from start to end--about 7-10X that at the entrance.

Electric arc furnaces at the Alcoa facility and other metal fab locations are another set of very large loads where anything to level load is a benefit financially and operationally as well.

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[Ed Pawlowski]

Aren't you in the MA area? That seems to be a monopoly of the monopolies. Is the city getting a cut?

[krw]

I was referring to the OP's comment about the 2000kWh limit before the utility uses demand billing, even on residential customers.

Understood. I was referring only to small, residential, customers.

You locate those *next* to power generation. ;-) It's the largest cost.

[krw]

Me? Good God, man. I'm not nuts! I moved out of New England (Vermont), for good, four years ago. We live in Alabama, 100mi down the road from Dufas. ;-)

I don't think so. Everything (but water) is pretty cheap. Electricity is $.08/kWh and garbage is $15/month, both half what they're paying in Vermont. Property taxes are a quarter.

The downside is that there are a significant number of power outages. None long, just enough to be annoying. ...and no cable TV, yet (Charter did just come by, but I'm holding out for the city's "fiber to the house").

[dpb]

On 5/30/2011 2:27 PM, [e-mail] wrote: ...

Oh, sorry, missed that limited context intent.

No, I don't see it being particularly significant for residential customers for the most part other than, perhaps, the mcmansion-type w/ spa, pool and pool heaters, maybe the heated driveway thingie, etc., etc., etc., ... For the casual homeowner w/ a fridge and range and water heater, it's unlikely would make much difference. But, it would be simple enough to deal w/ things like the water heater and other loads not sharing "on" time.

Alcoa is where it is in large part owing to TVA in the WW II era as is Oak Ridge (gas diffusion plants and earlier magnetic separation) for the Manhattan Project. Rural at the time w/ plenty of water for power. Kingston Fossil was built subsequently for the expansion of the facilities during the '50s arms race.

While relatively close, the Al plant isn't right next door to generation facilities but the smelter is closer. It's kinda spooky driving along I40 when one of the loaded flatbeds passes at about 80-85 mph w/ that vat of hot Al on the way to the casting mill. There have been a couple of accidents where they've spilled one; it tends to leave crispy things all around... :(

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[krw]

I would think it more important to get those things off "peak" times, where commercial users are the big users. I guess it depends on where the choke points are in the system.

I imagine it would.

[dpb]

...

...

Indeed. I would guess the limitation for residential is in transmission and substations as growth continues to get more spread out from urban centers. Little of that is directed to or through the areas that would be serving the heavy industrial users so don't think it would make much difference for most utilities from that standpoint.

I could see that load leveling could, on a wide-enough scale, potentially allow one to forestall otherwise necessary retail market grid enhancements as a potential (altho distribution wasn't my primary area when doing work w/ the utilities; I was mostly generation-side I&C R&D for enhanced measurements during most of time w/ the fossil guys; prior to that while still in the nuke generation arena it was all very physics oriented and very little to do w/ anything more than remotely connected to actually generating power--only in that it took somebody to keep the reactors purring to boil the water in the SGs and deep in the bowels of the computational physics models used for those calculations are my thumb prints... :) )

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[Evan]

The Kill-O-Watt meter can only measure one load at a time... It might take him weeks or months to measure all the devices using power in his office considering he has to also keep doing his actual job at the same time... An emon demon will measure all of the power flowing through an entire 3-phase panel...

That is assuming facts not in evidence... The OP has clearly stated that there is only one electrical meter locked up inside a cabinet that no one in the building has access to, only the meter reader can open it... The OP also has stated that whatever office he works in is the only occupant in the building... OP also described that the "main wires" split off into several different panels...

You install an emon demon... You then operate each circuit individually to ascertain exactly what it is that the circuit is powering... Many places that see weird energy bills often have poorly labeled circuit breaker panels and tons of "mystery switches" on the wall which no one working there knows what they control...

For there to be any vampire loads would require other tenants in the building -- the OP has not said anything about the existence of such tenants (other than to say the building he works in belongs to his employer)...

Bull... A tamperer would not have access to a utility company lock which was obviously supplied by the power company to secure the main metering enclosure cabinet...

Yup, the Kill-O-Watt can not measure hardwired loads... Only plugged in appliances... I once saw an office tenant that tried to save money by removing half the lamps from 4 lamp fluorescent fixtures and not re- lamping burnt out fixtures in a timely manner... Not re-lamping fluorescent fixtures on a predetermined schedule based on the designed life of the lamps being used is an error -- you will end up only getting 50% of the light output for the same consumption of power...

An emon demon gets wired up to a circuit breaker in the panel it is monitoring in order to sense the precise voltage on each phase... There are three sensor loops which clamp on the feeder conductors for each phase of the panel... No electronics on the basic emon demon model, its all in the little gray box...

The cost depends on what type of meter you want, the basic one just displays its reading on its face panel but there are other more advanced meters that can interface with a telephone for remote readings or integrate into a BAS system to track and graph power usage...

I remember the cost being $400 for a basic meter and upwards of $1,200 for an advanced one with all the options but it also depends on the amperage of the panel/circuit/equipment you want to monitor...

of>>>>>>>>>> nth level response to get as personal. =A0Can't everyone pull= in

[Gary Heston]

[ ... ]

Sometimes the "power company" does other things. In my case, they're also the water and gas companies, and handle billing for trash pickup and sewage (which is the same units as water, just a higher rate).

Gary