240 supply voltage harmoniser for domestic property 100A 16

[David108108]

Hi everyone,

I'm a newbie here, and this is my first post. Thanks for taking the time to read through it.

I have a client who recently used an EMI Power Line Monitor to measure noise on their mains supply. This device can be plugged into any socket around the house to detect noise. Here’s a brief description of the monitor:

Product Description:

The Line EMI Meter measures electromagnetic interference (EMI) in a single-phase AC power line. It plugs into a wall outlet and does not require a battery. The device immediately displays total line noise in millivolts peak to peak (ranging from 1999.9 mVp-p with a resolution of 0.1 mVp-p) within the frequency range of 10 KHz to 10 MHz (where sensitivity is half of the maximum sensitivity). It also has a speaker that plays the sound of the EMI, amplitude demodulated, which helps identify the source of the interference (e.g., AM or shortwave radio stations, motors, or electric arcs).

A good reading on this meter would be around 400 mV, but my client was getting a consistent reading of 1400 mV, indicating a significant increase in noise. I asked if there had been any recent changes in the house or nearby. Here’s what he mentioned:

The neighbor on the left installed solar panels.
The neighbor on the right installed a garden WiFi booster.
There were recent works carried out on his street.
His detached house has a TT earthing arrangement. Here’s my preliminary diagnosis:

There could be DC transient voltage from the neighbor’s solar panel inverter, possibly causing DC leakage to ground.
The WiFi booster from the neighbor on the right might be causing interference.
The street works might have introduced more noise into the incoming mains supply.
The EMI monitor registered the strongest noise level when plugged into a kitchen socket, but high readings were also observed in various other parts of the house. This likely rules out a faulty circuit.

I would greatly appreciate any input or advice to assist my client in resolving this issue.

Thank you!

 

[jghrist]

I'd look first for sources within the house. Turn off breakers one at a time to see if the interference stops.

 

[Heaviside1925]

OP,
I have not heard of these being anything but a novelty where I'm from in terms of residential use. Are these common in GB residences? (assuming this by your profile) I think you are possibly putting too much brain power into this IF this is not causing any other issues. Outside of the items you mentioned, it could be from a myriad of other sources. Maybe recommend your client talk to their neighbors and seeing if you client can plug this in at the neighbors' houses. Another option, if transient frequencies are a real concern to your client, they can install filtering to alleviate this.

 

[dpc]

Is your client experiencing any actual problems that could be a power quality issue? I agree with jghrist - first step would be to eliminate sources within the residence.

 

[waross]

Is your client experiencing any actual problems that could be a power quality issue?

Further to this, is power quality affecting your client's day to day life in any way?
1400 mV p-p
1400 seems like a large number but is it really?
That is only 1.4 Volts peak to peak,or a peak voltage of .7 Volts.
That suggests an RMS voltage of around 0.5 Volts.
Solution #1.
Throw the meter away and go back to living an unencumbered life.

Solution #2.
Step 1> Buy two of the smallest motor run capacitor available and connect them line to neutral.
Step 2> Throw the meter away and go back to living an unencumbered life.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[Heaviside1925]

Damn near spit my drink out when I read this.

Solution #1.
Throw the meter away and go back to living an unencumbered life.

Solution #2.
Step 1> Buy two of the smallest motor run capacitor available and connect them line to neutral.
Step 2> Throw the meter away and go back to living an unencumbered life.

So, the product description is verbatim from the manufacture's website. They seem like a legit company, but I do wonder if they may cater indirectly to the tin foil wearing hat community.

Not to knock your client but they paid money for a device to "detect" something that from all accounts was never an issue in the first place. How is this person your client? Did they actually hire an electrical engineer to come diagnose this "problem"? Not meaning to come across confrontationally but something doesn't smell quite right but maybe there is more to this story.

 

[wcaseyharman]

There are EMI “sniffers” that can pinpoint direction of EMI sources. I was talking to a troubleman (service lineman) and he has an additional task of locating EMI sources on the distribution system that interfere with radio signals like HAM radio. Sounds like it’s quite the science.
You might consider some of those tools to attempt to pinpoint the EMI source.

 

[David108108]

Thank you all for your much-appreciated input and ideas.

To answer some of the questions posted above:

My client is one of those unfortunate individuals with EHS (Electro Hypersensitivity). I have worked with various people with varying degrees of EHS over the past few years, and I can confirm that it is not purely a psychological illness. I have conducted various blind tests to rule out this possibility. The client in question contacted me to check his house's electrical installation, as he has been experiencing a greater level of malaise over the past six months. This prompted him to recheck the readings with his socket line monitor. Initially,(pre 6 months) the reading was around 400 mV, but then something happened that caused the reading to go much higher. I have also checked sources within the house by isolating each circuit and removing appliances on the circuit. To rule out the device being faulty, I have asked the client to check it at a different property.

Heaviside: Filtering is my next port of call once I have completely ruled out the obvious. Do you think it would be worthwhile using a DC earth leakage clamp meter to check if there is any stray DC voltage coming into the property from outside sources? Or even AC leakage from Neutral Current Diversion (NCD) or other? The filters I have in mind are EMC/RFI Powerline filters such as the EMK 250v AC single-phase 100A filter or the TE Connectivity Corcom RPQ 100 A filter. This is outside my area of expertise, so I would appreciate any pointers with this. No, these EMI monitors are not common in UK homes; they are gadgets used by people concerned with EMF issues.

WCaseyharman: Thanks. My client has a TRiField TF2 meter, which detects electrical, magnetic, and high-frequency fields. The worst offenders in the house are the halogen 12v downlights.

The client spends most of his time inside a self made faraday cage aka his bedroom. The walls have 3 coats of EMF shielding graphite paint which is grounded to the CPC. Windows are also covered with EMF shielding net curtains etc.

Hope that helps answer some of the main questions.

Thanks again for your advice and input.

 

[David108108]

Update

Client has just informed me that the Line EMI monitor reading of 1400mV decreases to 1100 mV at night. Not sure if this is will be a useful clue or not.

 

[FacEngrPE]

within the frequency range of 10 KHz to 10 MHz

Likely the house wiring is acting as an antenna. Is the reading still high with the mains turned off? different combinations of branches (on or off) with the mains off may provide different results.
I once had to troubleshoot an RF interference problem in a noisy industrial environment. A spectrum analyzer was helpful in identifying the source, and understand how the source was coupling into the local environment.

 

[crshears]

My client is one of those unfortunate individuals with EHS (Electro Hypersensitivity).

An acquaintance of my wife suffers from this; I wouldn't previously have believed this, but it's real.

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

 

[3DDave]

The problem with focusing on EMF as a cause means that if there is some other, more likely, reason for the malaise that is now ignored. I hesitate to make any further suggestion as that might just be the root of another layer of anxiety.

Having been inside an MRI where the EMF is extremely high, I detected nothing except the noise from the magnets reacting to the variation in field so, while I understand how people can come to make what they feel is a connection, there isn't one.

Doing double blind testing is ordinarily required to confirm a hypothesis, but in psychological problems the sufferer has already built confirmation bias into their understanding of reality. It may also be they are detecting something else, a side effect of the EMF. For example, I have some CFL bulbs that have a noticeable whine because their little power supplies are operating at a frequency I can hear.

If you want, I suppose contacting a local HAM club would be the cheapest way. Describe the problem and see if they want to try to locate the source of the electrical noise; this is something that comes up in the hobby as neighbors often claim some problem is related to the HAM operation and it gives them a way to test their signal finding skills.

 

[waross]

I apologize for my flippant suggestion,partly.
I say partly because while I accept and recognize that your client has a real problem, I am still skeptical about the usefulness of the meter.
The first rule of trouble shooting is:
"Identify the root cause of the issue."
The second rule of trouble shooting is:
"Identify the root cause of the issue."

Likely the house wiring is acting as an antenna.

I agree that is a very strong possibility.
What does this mean?
The field is probably external.
We may install capacitors on individual circuits to get a "happy" meter reading but your client will still be subject to the external field.
If this is an induced voltage and you are successful in suppressing it at the main panel, the circuit conductors will still act as an antenna and you may still see a high reading at the receptacle. (And your client will still be subject to the electromagnetic field.

The Line EMI Meter measures electromagnetic interference (EMI) in a single-phase AC power line. It plugs into a wall outlet and does not require a battery.

That is unfortunate and limits the usefulness of the device.
If you are able to find a battery powered meter, connect 10 or 20 feet of wire to the device and trail it around the home.
Let's troubleshoot, but first a comment:
While your client is troubled by a meter indication of 1.4 Volts Peak to peak, does he realize that he is immersed in a very strong electromagnetic field driven by over 600,000 Milli-Volts peak to peak?

The first rule[/b] of trouble shooting is:
"Identify the root cause of the issue."
What is the issue?
"he has been experiencing a greater level of malaise over the past six months."
Fair enough.
Next step.
The second rule of trouble shooting is:
"Identify the root cause of the issue."
"Greater malaise."- Could be the weather, could be depression over political events, could be diet, and it could be an increased electromagnetic field.
Fair enough.
Let's examine the possibility of an increased electromagnetic field.
What can we do with the meter?
Take about 10 feet of single conductor and connect it CAREFULLY to the hot terminal of the meter.
See if this changes the reading.
Move the wire in a direction at right angles.
See if this changes the reading.
Get a step ladder and hang the wire as near vertical as possible.
See if this changes the reading.
Why are we doing this?
To determine if the circuit conductor is the source of the EMI or a receptor of the EMI.
If the circuit conductor is the source, the orientation of the test wire may have little effect on the meter reading.
If the circuit conductor is a receptor, the orientation of the test wire in the EMI field may affect the meter reading.
Do the test and hope for the best but know that the results may be inconclusive.
Do a test on the receptacle closest to the panel.
Then plug in an extension cord and with the cord as straight as possible, test with the meter at the end of the cord.
Route the cord in various directions and also vertically from the stepladder.
Markedly different readings on the meter are a strong indication that the EMI field is external.

The worst offenders in the house are the halogen 12v downlights.
I hope that the client has been able to rule these out as the source of the current issues.

Client has just informed me that the Line EMI monitor reading of 1400mV decreases to 1100 mV at night. Not sure if this is will be a useful clue or not.
This points to the solar system as a possible source.
It may still be power line conducted or a radiated field.
Power line conducted:
Try some capacitors to ground. DO NOT USE MOTOR STARTING CAPACITORS.
Motor starting capacitors are intended for short time use and will overheat and fail if connected continuously.
Capacitors may reduce or eliminate conducted EMI.

If the EMI is a radiated field, consider a Faraday shield.
call in a contractor for a quotation to cover the house with stucco.
Stucco is typically supported by either wire similar to chicken wire or by expanded metal.
Either one may be grounded thereby transforming the house into a Faraday shield.
Your client may paint the ceilings and cover the windows.

Note: the chicken wire like stucco wire may pass very short wavelength micro-waves.
The expanded metal not so much.

This is not my field either, but I have tried to go back to basic principles and hope that there are no "Unintended consequences" of which I am unaware.




--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[LittleInch]

The wiki article clearly written by a non believer...

https://en.wikipedia.org/wiki/Electromagnetic_hypersensitivity

This reminds me a bit about low frequency noise which some people are sensitive to and blamed on buried pipelines. Shown to be not related.

When you think about it its very unclear whether fixing the frequency issues on the house wiring is actually going to do any good.

Has he tried just isolating the house for a couple of days and see what happens (move the freezer next door). Not that I think its that, but might stop all this running around looking for a reason for the EMI.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Heaviside1925]

OP,
Your client is a victim. This is a $150 scam.

I will not comment on your client's condition but as noted by others, RF is everywhere. If you truly want to help your client, waross's stucco suggestion would be the most appropriate.

There could be DC transient voltage from the neighbor’s solar panel inverter, possibly causing DC leakage to ground.

NO, HOW?

The WiFi booster from the neighbor on the right might be causing interference.

NO, What frequency range do these operate?

The street works might have introduced more noise into the incoming mains supply

Again, NO, HOW?

To truly see what is going on as FacEngrPE noted, you would need a spectrum analyzer. Why? because any signal interacting with another signal is going to create a signal that will be parts of each. The only way you can decouple these individual signals is to run it through an FFT, which is what a spectrum analyzer does. My guess..... based on the amplitude and the fact that it reduces at night, is that you are picking up a broadcast signal from TV or radio. I would see if a new AM talk radio station went on the air in the last year. Aside from that, HAM radio or even powerline communication protocols could be a source.

Basics of radiation exposure!! Time, distance and shielding. You need a lot of power to send signal through the air. Sure, you can hold a meter next to something and pick something up but try stepping 5' away and see if you still can. Could there be signals transposed on the 50/60hz power? sure! but how are those signals going to be retransmitted through open air? Your sources of household EMF human exposure are going to be powerful sources that can transmit through open air. The sun, a supernova, a nuclear explosion, a HV overhead line that you are in close proximity to, a radio transmitter.

Another option is a wide band transistor radio with a strength meter. You can scroll through the frequencies and see what you pick up but these gadgets you are enlisting are just a waste of your client's money and fueling an ailment.

 

[FacEngrPE]

If you decide to use the stucco approach, make sure to specify that the sections of wire or slotted / expanded metal lathe be electrically connected to each other. The distance between these electrical connections can be important (see quarter wave trap).

 

[David108108]

Thank you all for your very enlightening responses. I would like to address each one of your posts over the weekend.

I want to make it clear that neither the client nor I are suggesting that the increased reading on the EMI monitor is directly linked to the client's increase in malaise over the past six months. However, given his level of sensitivity, what may seem inconsequential to us could make a significant difference to the client.

Why do I think this? Because I have seen how my very EHS friend, who has been housebound for seven years, living in a Faraday cage, is affected. I agree that there is also a psychological component, but it is definitely not entirely psychological.

My client participated in a series of blind or double blind (not sure) tests along with several other candidates to verify the authenticity of their EHS for a BBC documentary. He said that he got all the answers correct.
Unfortunately the documentary was never aired on national television.

1. FacEngrPe:Likely: "the house wiring is acting as an antenna. Is the reading still high with the mains turned off? different combinations of branches (on or off) with the mains off may provide different results.
I once had to troubleshoot an RF interference problem in a noisy industrial environment. A spectrum analyzer was helpful in identifying the source, and understand how the source was coupling into the local environment."

I agree that this is a probable cause however this monitor works off mains and I haven't seen one that is battery operated.

Do you think the Line EMI monitor can pick up signals from noise on circuit's Live conductors, CPC and from EMF entering the cable? Or is the plug primarily a power source to run the monitor and it is just picking up EMF from the environment? Its frequency range is 10KHz to 10MHz would that imply that it would not register any EMF in the GHz range which would rule out the Wifi booster in the neighbours garden?

Re the Spectrum analyzer helping you trace the cause of the RF interference. Do you recall the cause and were you able to remedy it?

Thanks for your reply.

 

[3DDave]

Substantial study on the subject:

https://www.sciencedirect.com/science/article/abs/pii/S0022399912003352

in this case the participants were randomly assigned to watch one of two media produced recordings. One was on the dangers of WiFi signals and the other on safety of mobile phone data. After this both groups were told they would be exposed to 15 minutes of "new type of WiFi signal." There was no actual signal. Those who watched the recording on danger of WiFi reported increased symptoms from the non-existent signal.

Apparently no study result of positive detection has been reproduced. This and professional ethics on the part of the BBC may have been the cause for not running the program.

 

[David108108]

3DDave: Great find, and thanks for posting the link. I understand that you might not believe in the EHS phenomenon, so there's no point in trying to convince you otherwise, especially since there are no conclusive double-blind studies to support it. However, I can't simply tell my client that he is imagining things. Even if his condition is influenced by his mind (which I don't believe it is), getting to the bottom of the increased readings on his EMI monitor could still be beneficial.

 

[David108108]

3DDave: "If you want, I suppose contacting a local HAM club would be the cheapest way. Describe the problem and see if they want to try to locate the source of the electrical noise; this is something that comes up in the hobby as neighbors often claim some problem is related to the HAM operation and it gives them a way to test their signal finding skills. "

How would they trace the issue ? Also using a spectrum analyzer?

Would this one do the trick?

https://www.amazon.co.uk/Upgraded-Spectrum-Analyzer-Frequency-Generator/dp/B0BVV6BHK9

Thank you