What wiring method can be used to limit EMF in a home where people can "feel" EMF?

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Dennis Alwon said:
Just got a call today about a woman who's daughter has issues with electromagnetic field's . Going there tomorrow morning and I'll see what's up. I am seeing more and more people like this. Sort of like a craze or fad -- like Gluten free---:)
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You have a guass meter right? Those are awesome in times like that :thumbsup::D










nicholaaaas said:
Go play in the panel and say its all good now

Sent from my Nexus 9 using Tapatalk
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With a megger looking for wiring errors. Since when is leaving/not mentioning known code violations part of the job?
 
Didn't read entire thread so excuse me if I'm restating something.

Electro-magnetic fields; are two different fields. Electric and magnetic. Electric fields are quite easy to mitigate. Magnetic, not so easy.

Magnetic fields is the are under scrutiny; and logic wants to tell us "bury the T-lines". But, science says nope. Magnetic fields are not merely mitigated by conduit and earth. Distance is actually your best fried as the field drops off with the square of the distance, i.e. very quickly. Burying them actually brings them closer.

Now, in 1992 I was fortunate to have worked on some studies being done with regard to EMF. It was becoming all the rage. I personally, was responsible for taking a hefty amount of measurements to determine magnetic field strengths and develop a report. I looked at not only overhead lines, but underground distribution as well. The measurements confirmed the calculations/expectations. But interestingly, I was playing around with the meter at home and realized something; and thus the study was expanded to cover household appliances. I like to think we (was working with two PhD profs through EPRI) were the early ones that found household appliances can have much higher measured magnetic fields compared to HV T-lines; because of distances.

I won't try to give all the results because shortly after, and since that time there have been many, many studies done. I did run across a simple document by LIPA, called "Magnetic Field Levels Around Homes" that has some good easy to understand info.

Keeping in mind that any study done or information presented by a utility company is probably going to be very much geared toward downplaying any negative issues.
 
I wish Karl would have talked about the studies on electromagnetic field's a bit to explain why he feels that electromagnetic field's are not good. We do know that 300.3(B) eliminates magnetic fields when conduit is in use but we have an exception that allows non ferrous raceways to run the neutral separate from the feed. 300.3(B)(3)
 
Dennis Alwon said:
Did you know that Karl Riley is a member here and also a moderator
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I heard a member but not a mode! That's awesome :D:D



Dennis Alwon said:
I wish Karl would have talked about the studies on electromagnetic field's a bit to explain why he feels that electromagnetic field's are not good. We do know that 300.3(B) eliminates magnetic fields when conduit is in use but we have an exception that allows non ferrous raceways to run the neutral separate from the feed. 300.3(B)(3)
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Same here, he knows exactly what he is talking about. He is truly an expert in this field. :D

I wish he would come here and post more often. This is a great thread for him to explain.


Do you know if his book comes on PDF download?
 
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[QUOoanoke;1613333]Hopefully Dennis Alwon will see this and respond. he is well versed on EMF.[/QUOTE]
Well as I am told emf above 10 Gauss is detrimental to health. The use of twisted pair cables and FMC EMT solidly bonded. Paired with emi rfi barrier wallboard will work for your job.
 
How are they wired though

Ones I've done are all rigid conduit, all connections welded 360 degrees (all around).

Boxes with plated faying surfaces 1/4" wide or more, cover screw spacing 1 inch or less or gasketed with conductive gasket.

Anything with a similarity to switches or outlets, there is a LC filter on anything exiting the boxes or equipment. Have also used outlets and switches with EMI tight screw on covers that can only be removed when there is no tempest data present.
 
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mbrooke said:
How are they wired though? If you can share the none confidential methods in reducing EMF?
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Sorry I had not seen your post.

I was not a worker on the job but I was asked questions about some of the specs and how they complied with the NEC. That was easy, the specs required violating the NEC. One of the items I remember was that none of the conduits passing from the unsecured space into the secured space could be electrically continuous. They had to use some specified or provided fitting to break the continuity of the raceway at the wall.

Once inside I think we used MC however as I said I was never on site.
 
iwire said:
Sorry I had not seen your post.

I was not a worker on the job but I was asked questions about some of the specs and how they complied with the NEC. That was easy, the specs required violating the NEC. One of the items I remember was that none of the conduits passing from the unsecured space into the secured space could be electrically continuous. They had to use some specified or provided fitting to break the continuity of the raceway at the wall.

Once inside I think we used MC however as I said I was never on site.
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Its ok :)

No idea what breaking the conduit up does, but if it gets the job done why not.
 
junkhound said:
EMF reception:

Back in 1955 or so after I had my first silver tooth filling, my uncle showed me how you could take a piece of aluminum foil and an old motor brush and hold them between your teeth and actually hear the local AM radio station.
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That hurts my teeth just to think about it. Over the years I have had most/all of my silver fillings replaced, but I still remember how it feels to bite down on a piece of foil with silver fillings. OUCH!
 
ggunn said:
That hurts my teeth just to think about it. Over the years I have had most/all of my silver fillings replaced, but I still remember how it feels to bite down on a piece of foil with silver fillings. OUCH!
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You had to be able to make a point contact diode as one part of the circuit (not impossible with properly blended amalgam, but much easier with a galena inclusion) to detect the AM.
And I think many local AM stations were higher power back then.
 
GoldDigger said:
You had to be able to make a point contact diode as one part of the circuit (not impossible with properly blended amalgam, but much easier with a galena inclusion) to detect the AM.
And I think many local AM stations were higher power back then.
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I had a crystal radio set as a kid; same principle, I guess.
 
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