X10 Community Forum
💬General Category => General Discussion => Topic started by: dave w on February 23, 2017, 09:02:06 PM
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WARNING -Long, blathering, unfocused, comment and question follows:
The local Duke Energy power company installed a new smart meter at our house in mid November. We know the Duke Eschelon PLC meters caused headaches to X10 users in Ohio when they were installed there. I wonder if I might have a problem with the iTron "Open Way" meter. This "problem" however is diametrically opposite the Eschelon problem. The iTron uses WiFi to transmit data to a local node which then sends the data via cell phone network to their local HQ. So the meter does not affect X10 in the house, but I wonder if X10 affects the smart meter.
The November bill showed the daily kWh average was 43kWh on the old meter but jumped to 48kWh for the last half of the month under the new meter. Since the weather was cooling I did not think much of it. However my December bill was unexplainably high IMO. It was 1000kWh higher than the December 2015 bill. December 2015 had a monthly temp average that was only a few degrees warmer than 2016. So where did the increase come from(?). No new appliances, no family or friends staying with us, and I ruled out weather. So I wondered if X10 could be influencing the smart meter. I know it seems absurd. But here is my feeble minded reasoning.
The Open Way samples current being drawn by the house, and samples the incoming voltage. Although the reference manual does not explicitly state it, I get the impression these two measurements are treated separately until fed to the processor for wattage calculation. The sample rate is 1920 samples per second, or 32 samples per cycle. So I wonder if the three X10 pulses (for three phase use) imposed on each positive and negative half cycles, if falling into the voltage sample window of the Open Way A-D converters could cause the meter to "see" a slightly higher voltage than that actually being supplied.
During an X10 command this would affect almost 50 of the 60 cycles each second. Also since I have a "flame thrower" XTBIIR repeater, would the inflated voltage fool the meter in to thinking a higher wattage is being consumed by the home, or is it so small and insignificant to not affect the meter calculations.
Dressed in as much intimidating clothing as I could find in the closet (a "Motorola" ball cap, a "Bechtel - URS VX Neutralization Project" jacket) I took this query to the local Duke office and talked to one of the field engineers who knew vaguely what X10 was from the Ohio Eschelon problems. Apparently I piqued his interest because he said he would try and contact iTron about it. Later that day I got a call from another Duke engineer in Ohio to discuss my queries. (I get the impression that "X10" is still a sensitive spot for Duke). It was really difficult to get them to understand the problem, or at least my question, as they kept twisting the question until it became a question of how much wattage the X10 devices themselves consume. B:(
Reminds me of the old days with similar discussions between a Motorola field tech and the Bell Telephone tech he was talking to, while trying to set remote radio repeater control tones over a dedicated phone line. "The problem is at the your end" clamed each of the technicians . The second Duke engineer is to call again tomorrow.
To be continued...
I welcome any technical musing about this subject.
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I am no EE or electrician so my response is simply based on speaking to my local PUD in the past. When I was trying to determine how to track my energy usage, they explained how my meter read the power usage (too complicated for me to try to describe). Basically there are a few parameters that get set and when multiplied out, the usage pops out. There was a multiplier that is used for the specific meter (mechanical type, so probably different than yours) that they initially reported to me incorrectly. After working with their number for a week or two, I called back and they double checked and found it was different for my specific setup.
TL;DR They could have screwed up a setting for the meter that is causing you to be charged too much OR your old meter had a wrong parameter that was allowing you to be undercharged. If not that, I have nothing else to offer.
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During an X10 command this would affect almost 50 of the 60 cycles each second. Also since I have a "flame thrower" XTBIIR repeater, would the inflated voltage fool the meter in to thinking a higher wattage is being consumed by the home, or is it so small and insignificant to not affect the meter calculations.
Three-phase transmission is disabled by default in the XTB-IIR unless specifically enabled through a mode option, so only the zero-crossing burst would have the stronger XTB-IIR signal.
While I don't have technical details on the meter, I suspect it may be doing real-time multiplication of voltage and current over the waveform. That's what we did for monitoring power for gyro wheel supplies decades ago. Relatively little power is delivered over the first millisecond of the waveform when the X10 signal is transmitted.
But even if what you propose is true, the amount of time that X10 signals are transmitted compared with the amount of time in a day would be insignificant unless you have a VERY active X10 system sending commands almost constantly.
In this world of complex electronic loads, it could just be that the new meter is better at measuring power consumed by low power factor loads than the old meter.
Jeff
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But even if what you propose is true, the amount of time that X10 signals are transmitted compared with the amount of time in a day would be insignificant unless you have a VERY active X10 system sending commands almost constantly.
In this world of complex electronic loads, it could just be that the new meter is better at measuring power consumed by low power factor loads than the old meter.
I had forgot the XTBIIR does not transmit anything other than the phase one signal at zero crossing. That pretty much takes the wind out of my sails although the system is pretty busy. The system logged over 1260 X10 receives and transmits over the past five hours. It settles down late at night to a mere 600 commands in five hours.
The local paper, last week, said many people are complaining about their recent power bills jumping up. So far Duke's excuse has been to blame it on many meter reading errors. (most of the readers will lose their jobs as smart meter installs progress). I had wondered about the power factor but assumed duke would try and educate the public. So far there has not been a peep about it.
Thanks for the insight
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I know this thread is a few months old, but did you check the billing dates for the periods you're comparing? My utility company (and I know others do this too) sometimes vary the dates of the billing cycle up to a few days in either direction - which can make the billing cycle get longer or shorter from one year to the next. A few extra days might explain some of the additional power usage. Something similar happened to a neighbor of mine. For whatever reason, the utility didn't issue him a bill one month, so his next bill included the charges for both months.
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I know this thread is a few months old, but did you check the billing dates for the periods you're comparing?
Hi Noam,
Yes I did check the number of billing days, which were the same between December 2015 and Dec 2016. My bills for last three months are in line with one year earlier, so it looks like the problem was, as Duke contended, meter reader errors. Likely on purpose because a number of readers were losing their jobs.
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.........My bills for last three months are in line with one year earlier, so it looks like the problem was, as Duke contended, meter reader errors. Likely on purpose because a number of readers were losing their jobs.
I am in Ohio and was an early receiver of a new smart meter. I didn't experience any noticeable or measureable changes in eclectic usage/cost. The wife and I are pretty frugal and aren't big utility users... so it wouldn't take much for us to notice (either).
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.........My bills for last three months are in line with one year earlier, so it looks like the problem was, as Duke contended, meter reader errors. Likely on purpose because a number of readers were losing their jobs.
I am in Ohio and was an early receiver of a new smart meter. I didn't experience any noticeable or measureable changes in eclectic usage/cost.
Thanks Dave, good to know. Is your meter an iTron?
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It was Echelon meters that had issues and then only in a area in SW Ohio.
http://forums.x10.com/index.php?topic=22508.msg146262#msg146262 (http://forums.x10.com/index.php?topic=22508.msg146262#msg146262)
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..... and then only in a area in SW Ohio.
In SW Oh... but (just checked) I have the Landis+Gyr meter.