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Trust your what-hour err watt hour meter

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  Trust your what-hour err watt hour meter David Lesher <wb8foz@panix.com> - 2017-03-06 17:25 +0000
    Re: Trust your what-hour err watt hour meter John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-06 10:29 -0800
      Re: Trust your what-hour err watt hour meter bitrex <bitrex@de.lete.earthlink.net> - 2017-03-06 14:10 -0500
        Re: Trust your what-hour err watt hour meter John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-06 14:21 -0800
          Re: Trust your what-hour err watt hour meter bitrex <bitrex@de.lete.earthlink.net> - 2017-03-06 18:20 -0500
            Re: Trust your what-hour err watt hour meter John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-06 16:35 -0800
              Re: Trust your what-hour err watt hour meter bitrex <bitrex@de.lete.earthlink.net> - 2017-03-06 19:53 -0500
                Re: Trust your what-hour err watt hour meter John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-06 17:08 -0800
                  Re: Trust your what-hour err watt hour meter bitrex <bitrex@de.lete.earthlink.net> - 2017-03-07 13:05 -0500
                    Re: Trust your what-hour err watt hour meter John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-07 10:43 -0800
                      Re: Trust your what-hour err watt hour meter Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-03-07 14:21 -0500
        Re: Trust your what-hour err watt hour meter whit3rd <whit3rd@gmail.com> - 2017-03-06 18:36 -0800
    Re: Trust your what-hour err watt hour meter rickman <gnuarm@gmail.com> - 2017-03-06 14:52 -0500
      Re: Trust your what-hour err watt hour meter George Herold <gherold@teachspin.com> - 2017-03-06 12:04 -0800
        Re: Trust your what-hour err watt hour meter rickman <gnuarm@gmail.com> - 2017-03-06 15:15 -0500
        Re: Trust your what-hour err watt hour meter Jon Elson <jmelson@wustl.edu> - 2017-03-06 14:28 -0600
          Re: Trust your what-hour err watt hour meter John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-06 16:41 -0800
      Re: Trust your what-hour err watt hour meter Jon Elson <jmelson@wustl.edu> - 2017-03-06 14:26 -0600
        Re: Trust your what-hour err watt hour meter bitrex <bitrex@de.lete.earthlink.net> - 2017-03-06 15:30 -0500
      Re: Trust your what-hour err watt hour meter bitrex <bitrex@de.lete.earthlink.net> - 2017-03-06 15:28 -0500
        Re: Trust your what-hour err watt hour meter rickman <gnuarm@gmail.com> - 2017-03-06 16:04 -0500
        Re: Trust your what-hour err watt hour meter Jeff Liebermann <jeffl@cruzio.com> - 2017-03-06 16:22 -0800
          Re: Trust your what-hour err watt hour meter David Lesher <wb8foz@panix.com> - 2017-03-09 16:03 +0000
            Re: Trust your what-hour err watt hour meter Wim Ton <wim.ton@gmail.com> - 2017-03-09 12:39 -0800
            Re: Trust your what-hour err watt hour meter Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-03-09 15:46 -0800
    Re: Trust your what-hour err watt hour meter TTman <pcw1.cad@ntlworld.com> - 2017-03-06 21:48 +0000
      Re: Trust your what-hour err watt hour meter John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-06 14:32 -0800
        Re: Trust your what-hour err watt hour meter David Lesher <wb8foz@panix.com> - 2017-03-09 16:30 +0000
          Re: Trust your what-hour err watt hour meter makolber@yahoo.com - 2017-03-09 12:27 -0800
            Re: Trust your what-hour err watt hour meter Neon John <no@never.com> - 2017-03-09 15:43 -0500
              Re: Trust your what-hour err watt hour meter Wim Ton <wim.ton@gmail.com> - 2017-03-09 12:49 -0800
                Re: Trust your what-hour err watt hour meter Neon John <no@never.com> - 2017-03-11 11:11 -0500
                  Re: Trust your what-hour err watt hour meter Wim Ton <wim.ton@gmail.com> - 2017-03-11 12:28 -0800
              Re: Trust your what-hour err watt hour meter John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-09 12:59 -0800
                Re: Trust your what-hour err watt hour meter Neon John <no@never.com> - 2017-03-11 17:38 -0500
                  Re: Trust your what-hour err watt hour meter John Larkin <jjlarkin@highlandtechnology.com> - 2017-03-11 15:04 -0800
          Re: Trust your what-hour err watt hour meter Wim Ton <wim.ton@gmail.com> - 2017-03-09 12:47 -0800
      Re: Trust your what-hour err watt hour meter Neon John <no@never.com> - 2017-03-08 20:05 -0500
        Re: Trust your what-hour err watt hour meter Phil Allison <pallison49@gmail.com> - 2017-03-11 17:42 -0800
    Re: Trust your what-hour err watt hour meter Phil Allison <pallison49@gmail.com> - 2017-03-06 17:53 -0800
    Re: Trust your what-hour err watt hour meter Cursitor Doom <curd@notformail.com> - 2017-03-07 17:58 +0000
    Re: Trust your what-hour err watt hour meter Anthony Stewart <tony.sunnysky@gmail.com> - 2017-03-09 15:31 -0800

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#450512

On 3/6/2017 3:28 PM, bitrex wrote:
> On 03/06/2017 02:52 PM, rickman wrote:
>> On 3/6/2017 12:25 PM, David Lesher wrote:
>>> <https://www.utwente.nl/en/news/!/2017/3/313543/electronic-energy-meters-false-readings-almost-six-times-higher-than-actual-energy-consumption>
>>>
>>>
>>>
>>> ......"The inaccurate readings are attributed to the energy meter's
>>> design, together with the increasing use of modern (often
>>> energy-efficient) switching devices. Here, the electricity being
>>> consumed no longer has a perfect waveform, instead it acquires
>>> an erratic pattern. The designers of modern energy meters
>>> have not made sufficient allowance for switching devices of
>>> this kind. When they dismantled the energy meters tested, the
>>> researchers found that the ones associated with excessively high
>>> readings contained a 'Rogowski Coil' while those associated with
>>> excessively low readings contained a 'Hall Sensor'."
>>>
>>> I smell lawsuits since the PoCo's have been removing the
>>> old meters en mass....
>>
>> I've got a house with a broken meter.  The old analog style, the big
>> wheel doesn't turn anymore.  I guess after 50 years they wear out.  I
>> wonder how many months of $5 utility bills it will take for them to
>> figure it out?
>>
>
> Even when they used analog meters around here back in the day instead of
> the WiFi ones or whatever they have now, I don't think they read the
> meter every month but often just billed on "estimated usage" by looking
> at a representative sample

That's the part that surprises me.  Maybe they know the house is empty 
and the few readings don't throw any alarms.  The normal usage is nearly 
zero until the winter heat is turned on which is just three months. 
It's already off.

-- 

Rick C

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#450533

On Mon, 6 Mar 2017 15:28:18 -0500, bitrex
<bitrex@de.lete.earthlink.net> wrote:

>Even when they used analog meters around here back in the day instead of 
>the WiFi ones or whatever they have now, I don't think they read the 
>meter every month but often just billed on "estimated usage" by looking 
>at a representative sample

On the left coast, PG&E uses 900 MHz spread spectrum for smartmeters,
not wi-fi.  

If I want, I can get hourly usage graphs from their web pile.  Sample:
<http://802.11junk.com/jeffl/crud/PGE-usage-sample.jpg>
The problem is that it's always 2-3 days behind and the web pages are
really slow to load.

I can also download the data.  This is a spreadsheet that I threw
together to analyze cost and consumption trends to see how much I was
saving by switching to LED lights, putting timers on phantom loads,
and a little solar power during the summer:
<http://802.11junk.com/jeffl/crud/PG&E-to-2017-03-03.xls>
Notice how my monthly power consumption is going down (lower graph)
while my monthly charges are going up.  Grrr...

Some of this might be estimated usage, but I doubt it. 

-- 
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558

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#450983

Jeff Liebermann <jeffl@cruzio.com> writes:


>On the left coast, PG&E uses 900 MHz spread spectrum for smartmeters,
>not wi-fi.  

And stupidly. 

The electric meters, with a convenient unlimited source of
power, run as a mesh network eventually reaching a node up in
their space atop a pole. Look for two broomsticks.

The node uses cellular data to report upstream, unless it's a
dead spot when they have POTS.

The gas meters, relying on a lithium battery, use the lowest
transmit power by talking to the nearest electric meter.....

^H^H^H^H^H
Error Error

No, the gas meters do NOT use the electric mesh; they have to
separately talk directly to the pole node.... 

And by the way, if you are in the mountains w/ no cell coverage,
PG&E drives a car up with a mobile interrogator..

^H^H^H^H^H
Error Error

....drives a car up, parks, and the reader walks to each meter
to read by hand.

I was dumbfounded when their employee told me this...
 
-- 
A host is a host from coast to coast.................wb8foz@nrk.com
& no one will talk to a host that's close..........................
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

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#451033

> 
> The electric meters, with a convenient unlimited source of
> power, run as a mesh network eventually reaching a node up in
Not exactly unlimited, in many countries there is a limit to the power consumption of an electricity meter. In Europe, something like 5 Watt/phase, but some brands require only 1 Watt/phase. B.t.w. this consumption is generally not metered. You have to pay it anyway through your infrastructure charges.

BR, Wim

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#451075

Den torsdag den 9. marts 2017 kl. 17.03.07 UTC+1 skrev David Lesher:
> Jeff Liebermann <jeffl@cruzio.com> writes:
> 
> 
> >On the left coast, PG&E uses 900 MHz spread spectrum for smartmeters,
> >not wi-fi.  
> 
> And stupidly. 
> 
> The electric meters, with a convenient unlimited source of
> power, run as a mesh network eventually reaching a node up in
> their space atop a pole. Look for two broomsticks.
> 
> The node uses cellular data to report upstream, unless it's a
> dead spot when they have POTS.
> 
> The gas meters, relying on a lithium battery, use the lowest
> transmit power by talking to the nearest electric meter.....
> 
> ^H^H^H^H^H
> Error Error
> 
> No, the gas meters do NOT use the electric mesh; they have to
> separately talk directly to the pole node.... 
> 
> And by the way, if you are in the mountains w/ no cell coverage,
> PG&E drives a car up with a mobile interrogator..
> 
> ^H^H^H^H^H
> Error Error
> 
> ....drives a car up, parks, and the reader walks to each meter
> to read by hand.
> 
> I was dumbfounded when their employee told me this...
>  

I think the postal service reads meters in some places here 
a receiver on their cars read them as they drive around 
delivering mail. 

I don't know if it still exist but there also used to be a tracking 
device for bicycles and such. tiny super low power rf transceiver 
hidden on the bike, every time a postal van is in range a gps 
coordinate stored in a database so you could lookup it up if it went 
"missing"  

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#450515

On 06/03/2017 17:25, David Lesher wrote:
> <https://www.utwente.nl/en/news/!/2017/3/313543/electronic-energy-meters-false-readings-almost-six-times-higher-than-actual-energy-consumption>
>
> ....."The inaccurate readings are attributed to the energy meter's
> design, together with the increasing use of modern (often
> energy-efficient) switching devices. Here, the electricity being
> consumed no longer has a perfect waveform, instead it acquires
> an erratic pattern. The designers of modern energy meters
> have not made sufficient allowance for switching devices of
> this kind. When they dismantled the energy meters tested, the
> researchers found that the ones associated with excessively high
> readings contained a 'Rogowski Coil' while those associated with
> excessively low readings contained a 'Hall Sensor'."
>
> I smell lawsuits since the PoCo's have been removing the
> old meters en mass....
>
That's worrying for Joe Bloggs public. How are they ever going to 
contest a Smart Meter's accuracy ? How do we know that the old moving 
dial meters will be accurate with all today's 'switcher' electronics ?
I think we all know that they respond correctly to a zero phase lead/ 
lag and start to be inaccurate as the phase lead/lag changes ( power factor)

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

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#450519

On Mon, 6 Mar 2017 21:48:22 +0000, TTman <pcw1.cad@ntlworld.com>
wrote:

>On 06/03/2017 17:25, David Lesher wrote:
>> <https://www.utwente.nl/en/news/!/2017/3/313543/electronic-energy-meters-false-readings-almost-six-times-higher-than-actual-energy-consumption>
>>
>> ....."The inaccurate readings are attributed to the energy meter's
>> design, together with the increasing use of modern (often
>> energy-efficient) switching devices. Here, the electricity being
>> consumed no longer has a perfect waveform, instead it acquires
>> an erratic pattern. The designers of modern energy meters
>> have not made sufficient allowance for switching devices of
>> this kind. When they dismantled the energy meters tested, the
>> researchers found that the ones associated with excessively high
>> readings contained a 'Rogowski Coil' while those associated with
>> excessively low readings contained a 'Hall Sensor'."
>>
>> I smell lawsuits since the PoCo's have been removing the
>> old meters en mass....
>>
>That's worrying for Joe Bloggs public. How are they ever going to 
>contest a Smart Meter's accuracy ? How do we know that the old moving 
>dial meters will be accurate with all today's 'switcher' electronics ?
>I think we all know that they respond correctly to a zero phase lead/ 
>lag and start to be inaccurate as the phase lead/lag changes ( power factor)
>
>---
>This email has been checked for viruses by Avast antivirus software.
>https://www.avast.com/antivirus

The old disk meters were very accurate for sinewave loads, at any
power factor. In fact, it's hard to design an electronic meter as good
as the old disks, one that will pass ANSI C12. About the only spec
that's easier for an electronic meter to pass is tilt sensitivity.

I'm sure any smart meter has to be lab tested to C12 levels. Mine
were.

The mechanical meters were better for stuff like lightning strikes,
too.

Mathematically, as long as the voltage waveform remains sinusoidal,
there is no energy in the current harmonics.


-- 

John Larkin         Highland Technology, Inc
picosecond timing   precision measurement 

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

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#450992

John Larkin <jjlarkinxyxy@highlandtechnology.com> writes:


>The old disk meters were very accurate for sinewave loads, at any
>power factor. In fact, it's hard to design an electronic meter as good
>as the old disks, one that will pass ANSI C12. About the only spec
>that's easier for an electronic meter to pass is tilt sensitivity.

>I'm sure any smart meter has to be lab tested to C12 levels. Mine
>were.

>The mechanical meters were better for stuff like lightning strikes,
>too.

>Mathematically, as long as the voltage waveform remains sinusoidal,
>there is no energy in the current harmonics.


But the issue at hand is all about non-sinusoidal waveforms, is
it not?  Does C12 even cover such? It's only recently that such
have predominated in resi loads.

[A friend got dragged into mess at a cement plant. His gadget
depended on zero crossing detection. There was a mixer with a
VFD; said mixer was a several thousand horsepower motor. At
some speeds, it took such big chunks out of the plant feed that
"zero" was not where it should be....]


-- 
A host is a host from coast to coast.................wb8foz@nrk.com
& no one will talk to a host that's close..........................
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

[toc] | [prev] | [next] | [standalone]

#451031

> 
> >The old disk meters were very accurate for sinewave loads, at any
> >power factor. In fact, it's hard to design an electronic meter as good
> >as the old disks, one that will pass ANSI C12. About the only spec
> >that's easier for an electronic meter to pass is tilt sensitivity.


so what waveform will make them read LOW?

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#451034

On Thu, 9 Mar 2017 12:27:28 -0800 (PST), makolber@yahoo.com wrote:


>so what waveform will make them read LOW?

Mechanical meters, DC on the line.  That introduces eddy current drag
on the wheel just like the calibration and anti-creep magnets do.

Electronic meters?  Who knows.  probably varies by brand and metering
chip used, if any.

John
John DeArmond
http://www.neon-john.com
http://www.tnduction.com 
Tellico Plains, Occupied TN
See website for email address

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#451036

On Thursday, 9 March 2017 21:43:38 UTC+1, Neon John  wrote:
> On Thu, 9 Mar 2017 12:27:28 -0800 (PST), makolber@yahoo.com wrote:
> 
> 
> >so what waveform will make them read LOW?
> 
> Mechanical meters, DC on the line.  That introduces eddy current drag
> on the wheel just like the calibration and anti-creep magnets do.
> 
> Electronic meters?  Who knows.  probably varies by brand and metering
> chip used, if any.

Depends on the measurement technique; shunt, hall, Rogowski.
Wim

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#451318

On Thu, 9 Mar 2017 12:49:12 -0800 (PST), Wim Ton <wim.ton@gmail.com>
wrote:

>On Thursday, 9 March 2017 21:43:38 UTC+1, Neon John  wrote:
>> On Thu, 9 Mar 2017 12:27:28 -0800 (PST), makolber@yahoo.com wrote:
>> 
>> 
>> >so what waveform will make them read LOW?
>> 
>> Mechanical meters, DC on the line.  That introduces eddy current drag
>> on the wheel just like the calibration and anti-creep magnets do.
>> 
>> Electronic meters?  Who knows.  probably varies by brand and metering
>> chip used, if any.
>
>Depends on the measurement technique; shunt, hall, Rogowski.
>Wim

Not really, at least until the DC level gets high enough to saturate a
hall device.  What matters is the signal processing that comes after
the sensor and THAT depends on what chip is used.  Just like I said.

John
John DeArmond
http://www.neon-john.com
http://www.tnduction.com 
Tellico Plains, Occupied TN
See website for email address

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#451358

On Saturday, 11 March 2017 17:11:19 UTC+1, Neon John  wrote:
> On Thu, 9 Mar 2017 12:49:12 -0800 (PST), Wim Ton <wim.ton@gmail.com>
> wrote:
> 
> >On Thursday, 9 March 2017 21:43:38 UTC+1, Neon John  wrote:
> >> On Thu, 9 Mar 2017 12:27:28 -0800 (PST), makolber@yahoo.com wrote:
> >> 
> >> 
> >> >so what waveform will make them read LOW?
> >> 
> >> Mechanical meters, DC on the line.  That introduces eddy current drag
> >> on the wheel just like the calibration and anti-creep magnets do.
> >> 
> >> Electronic meters?  Who knows.  probably varies by brand and metering
> >> chip used, if any.
> >
> >Depends on the measurement technique; shunt, hall, Rogowski.
> >Wim
> 
> Not really, at least until the DC level gets high enough to saturate a
> hall device.  What matters is the signal processing that comes after
> the sensor and THAT depends on what chip is used.  Just like I said.

Saturating the measurement system is a well know fraud technique and certain meters will generate an 'excessive DC component' alarm. Same with disabling the power supply of some meters by saturating the core of the SMPS. 
The alarm can be followed up by the meter operator (braving pit-bull terriers and homeowners with firearms.
BR, Wim
PS. I work for a large meter manufacturer. 

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#451041

On Thu, 09 Mar 2017 15:43:30 -0500, Neon John <no@never.com> wrote:

>On Thu, 9 Mar 2017 12:27:28 -0800 (PST), makolber@yahoo.com wrote:
>
>
>>so what waveform will make them read LOW?
>
>Mechanical meters, DC on the line.  That introduces eddy current drag
>on the wheel just like the calibration and anti-creep magnets do.

There must be some box load that net slows down a disk meter.

>
>Electronic meters?  Who knows.  probably varies by brand and metering
>chip used, if any.
>
>John
>John DeArmond
>http://www.neon-john.com
>http://www.tnduction.com 
>Tellico Plains, Occupied TN
>See website for email address

Most meters are AC-coupled for the current measurement, and CTs may
saturate with DC, too.


-- 

John Larkin         Highland Technology, Inc
picosecond timing   precision measurement 

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

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#451380

On Thu, 09 Mar 2017 12:59:12 -0800, John Larkin
<jjlarkinxyxy@highlandtechnology.com> wrote:

>On Thu, 09 Mar 2017 15:43:30 -0500, Neon John <no@never.com> wrote:
>
>>On Thu, 9 Mar 2017 12:27:28 -0800 (PST), makolber@yahoo.com wrote:
>>
>>
>>>so what waveform will make them read LOW?
>>
>>Mechanical meters, DC on the line.  That introduces eddy current drag
>>on the wheel just like the calibration and anti-creep magnets do.
>
>There must be some box load that net slows down a disk meter.

I just searched around to make sure I haven't missed anything.  The
only two techniques that work without external evidence are
superimposing either DC or audio frequency AC.

placing strong magnets on the outside of the meter works too but is
kinda obvious to the meter reader.

I have several different brands of solid state meters.  On my bucket
list is to characterize them and see what it takes to make they read
incorrectly on a fairly high power factor load.

John

John DeArmond
http://www.neon-john.com
http://www.tnduction.com 
Tellico Plains, Occupied TN
See website for email address

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#451384

On Sat, 11 Mar 2017 17:38:53 -0500, Neon John <no@never.com> wrote:

>On Thu, 09 Mar 2017 12:59:12 -0800, John Larkin
><jjlarkinxyxy@highlandtechnology.com> wrote:
>
>>On Thu, 09 Mar 2017 15:43:30 -0500, Neon John <no@never.com> wrote:
>>
>>>On Thu, 9 Mar 2017 12:27:28 -0800 (PST), makolber@yahoo.com wrote:
>>>
>>>
>>>>so what waveform will make them read LOW?
>>>
>>>Mechanical meters, DC on the line.  That introduces eddy current drag
>>>on the wheel just like the calibration and anti-creep magnets do.
>>
>>There must be some box load that net slows down a disk meter.
>
>I just searched around to make sure I haven't missed anything.  The
>only two techniques that work without external evidence are
>superimposing either DC or audio frequency AC.
>

It wouldn't take a lot of power to jam a bunch of DC amps into a
circuit. That would have interesting effects on most any disk or
electronic meter.

I'm sure it's being done. Meters may have tamper detection.

I designed one meter for use in India, where some serious fraction of
the power is stolen... sort of like New York City. It had some
anti-theft hooks. Sadly, it never saw production.


-- 

John Larkin         Highland Technology, Inc

lunatic fringe electronics 

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#451035

> >The old disk meters were very accurate for sinewave loads, at any
> >power factor. In fact, it's hard to design an electronic meter as good
> >as the old disks, one that will pass ANSI C12. About the only spec
> >that's easier for an electronic meter to pass is tilt sensitivity.
> 
> >I'm sure any smart meter has to be lab tested to C12 levels. Mine
> >were.
> 
> >The mechanical meters were better for stuff like lightning strikes,
> >too.
> 
> >Mathematically, as long as the voltage waveform remains sinusoidal,
> >there is no energy in the current harmonics.
> 
> 
> But the issue at hand is all about non-sinusoidal waveforms, is
> it not?  Does C12 even cover such? It's only recently that such
> have predominated in resi loads.
> 
To reduce costs and assuming a more or less resistive load, domestic electricity meters only measure 'active energy', the part where current and voltage are in phase. 
For industrial customers, like your cement mill, the reactive 'energy' is measured and billed separately. 

BR, Wim
Yes, I know reactive is not energy but still burdens the network. 

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#450904

On Mon, 6 Mar 2017 21:48:22 +0000, TTman <pcw1.cad@ntlworld.com>
wrote:


>I think we all know that they respond correctly to a zero phase lead/ 
>lag and start to be inaccurate as the phase lead/lag changes ( power factor)

As someone who spent a year in TVA's meter shop during his
apprenticeship and who has a Fluke meter calibration bench and who was
a power metering consultant for a couple of decades, I can assure you
that any "we" who knows the above is badly mistaken.

Analog meters are calibrated to be +-0.25% at unity power factor at
the "CA" spec (usually 35 amps) and +-1% at +-0.4PF.  The meter must
maintain that level of accuracy for 10 years. That is TVA's standard
and they tend to have a major influence on US utility policy.

I'm currently at war with my power Co-Op.  They did have a wonderful
AMR/AMS that used the mechanical meter as the sensing element and
encoded wheel turns to be transmitted to the billing office.  The
system is called the Turtle system, in case you want to look it up.

Then they installed solid state meters.  My bill skyrocketed.  I have
a lab in my home and design induction heaters for manufacture
elsewhere.  None are PF corrected and the most powerful one is 15kW.

My analog meter, as verified by a second analog meter that I own,
accurately metered this load.  When the high bills arrived and I
complained, I got the usual pat on the head from the customer service
rep.  When I started throwing some metering terms around, I got to
talk to a (non-metering) engineer.  A more sophisticated pat on the
head.

So I set up a demo.  Load was a 9 track tape degausser that draws
about 15 amps but only about 40 true watts.  Both my analog meter and
their digital meter were videoed and a split screen edited.  I sent
that to the Co-Op General Manager with a note that said that my next
communication would come from my lawyer.

They came out in a few days and installed a new analog meter.  We're
back to the old system where I mark a post card every month with the
odometer reading and mail it in.  

We're still battling over past over-charges.

For anyone who has suffered a step change in their bill after an
electronic meter was installed, I suggest that you go to the trouble
of buying your own meter and socket and having it installed.  $15 and
$10 respectively from 

http://www.hialeahmeter.com/

Or hire a consultant like me (well, before I retired from that
business) who owns a revenue-grade clamp-on recording meter and have
him prepare a report on your actual usage vs what the electronic meter
is reading.  Worth your money in the long run.

John





John DeArmond
http://www.neon-john.com
http://www.tnduction.com 
Tellico Plains, Occupied TN
See website for email address

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#451413

Neon John wrote:


> 
> So I set up a demo.  Load was a 9 track tape degausser that draws
> about 15 amps but only about 40 true watts.  
>

** That load has a PF of 0.022 (a phase angle of 89degrees) which is exceptional.

Note that the installed power meter will read the losses in the cable feeding your load as well as in the load - which even if only 0.2 ohms would double the number. 

I understand modern meters sample the voltage and current many times each cycle and multiply the numbers to get instantaneous power, then average it to get a true power reading. 

With your example, the sampling rate would have to be very high to ensure an accurate result - more than 360 times per cycle.
 

 
.... Phil 

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#450550

David Lesher wrote:

 https://www.utwente.nl/en/news/!/2017/3/313543/electronic-energy-meters-false-readings-almost-six-times-higher-than-actual-energy-consumption
> 
>
> ....."The inaccurate readings are attributed to the energy meter's
> design, together with the increasing use of modern (often
> energy-efficient) switching devices. Here, the electricity being
> consumed no longer has a perfect waveform, instead it acquires
> an erratic pattern. The designers of modern energy meters
> have not made sufficient allowance for switching devices of
> this kind. When they dismantled the energy meters tested, the
> researchers found that the ones associated with excessively high
> readings contained a 'Rogowski Coil' while those associated with
> excessively low readings contained a 'Hall Sensor'."
> 

** The very high readings were obtained by combining a dimmer with CFL or LED bulbs. As many as 47 bulbs at once. 

Based on testing I did a few years back, this likely resulted in extremely high peak currents every half cycle. I reported this to my colleague Rod Elliot of ESP and he did similar testing. See here under the "Dimming" heading: 

http://sound.whsites.net/lamps/cfl.html

The majority of CFLs and LED lamps are not meant to be used with a dimmer and even those that claim to be "dimmable" require a particular type of dimmer to be used to avoid excessive peak currents. 

Despite what the article claims, the test was not a realistic one.

I would like to see full details of the test before taking it seriously. 



....   Phil

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