🔌General Home Automation > Powerline Control Reliability
Smart meter problem solved
JeffVolp:
We have a solution that has virtually eliminated the smart meter problem at one home in the Duke Cincinnati service area. That particular smart meter was communicating with its data aggregator at 75KHz and 86KHz. Those strong signals were near enough to the 120KHz passband that they were interfering with X10 communication.
Across-line filters in the home, even deep notch filters tuned to the smart meter frequency, were not sufficient in themselves. One thing observed was that the smart meter apparently transmitted an even stronger signal when an attenuator was placed across the line. And there appeared to be more communication attempts, increasing the likelihood of corrupting X10 signals.
My customer found a low-frequency "clamshell" ferrite filter to clamp over the incoming service entrance cables to add impedance to the smart meter signal. Initial testing was done with one filter clamped over each hot lead. Along with a filter to provide a low impedance load to the smart meter signal, a pair of the ferrite filters was the first step in restoring acceptable X10 operation.
Since then we have gone through a series of different internal filters and added more ferrite filters to the service entrance cables. The recommended solution is to use 2 or 3 ferrite filters on each of the "hot" service entrance cables, and a single shunt filter across the incoming 240VAC. The X10 XPNR is effective for the shunt filter, but a modified version of the XTB-TSS (Tuned Signal Sucker) performed better, particularly at the 86KHz frequency. Since that is closer to the X10 passband, it is more of a problem.
Best performance was actually obtained with an 86KHz notch filter across the 240VAC. However, tuning of a series-resonant notch is very sensitive to powerline inductance. The configuration of the installation being tested had relatively low inductance between the smart meter and where the filters were being installed, so the detuning from line inductance was not too severe. The series-resonant notch filter may not be the best general solution because of its sensitivity to detuning from powerline inductance.
I now have a small stock of the ferrite filters, with more on backorder. I will be purchasing parts to assemble more of the 250VAC XTB-TSS in the near future. Please contact me directly if you are interested in this fix.
Jeff
Knightrider:
Jeff,
First of all, you just moved up a notch on my hero list.
Second, is this really the financial responsibility of the homeowner to undo damage done by the utility?
BTW, it was John Wayne that just got knocked down a peg.
JeffVolp:
--- Quote from: Knightrider on January 23, 2012, 08:49:57 PM ---Second, is this really the financial responsibility of the homeowner to undo damage done by the utility?
--- End quote ---
Unfortunately, that is one question that I can't answer.
In reality, the utility company didn't "damage" anything. They just rendered equipment that worked fine for years unable to function properly anymore. Gee, I have several TVs and DVRs that are also in that category. (No, I don't own a HDTV flat screen yet.)
Jeff
Knightrider:
--- Quote from: JeffVolp on January 23, 2012, 11:16:39 PM ---
In reality, the utility company didn't "damage" anything. They just rendered equipment that worked fine for years unable to function properly anymore. Gee, I have several TVs and DVRs that are also in that category. (No, I don't own a HDTV flat screen yet.)
Jeff
--- End quote ---
Point well taken. It's just the thought that I can choose to purchase items that dirty up the powerline or not. Not sure I have a choice when it comes to a smartmeter install.
Cincydew:
I have been struggling with Duke since they installed the "smart meter" on my house last year. My X-10 system immediately began randomly activating lights. I can't get anyone to talk to me about a solution. I have seen some posts that suggest that in some cases Duke has done something to alleviate the problem. I am hoping that someone can direct me to the proper resource.
Bummed in Cincinnati.
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