# Best Wiring Method To Avoid EMF



## LAElectrician (Dec 8, 2009)

Hi guys,

I've got a customer who wants my company to re-wire some of his receptacles in his bedroom to lessen the amount of EMF he's picking up with his Gauss meter. I have no experience in this. 

Some of the material options I could re-wire with would be:
1. MC cable
2. Aluminum flex
3. Steel flex
4. Romex, but twist the Romex 

Anybody know anything about this?


----------



## CraigV (May 12, 2011)

Shield the room with copper mesh. Did he/you shut off the main to determine how much EMF he's reading from other sources? In many cases the home wiring is not a significant contributor.

Don't forget to wear your best tinfoil hat. If you put some egg salad between the layers it's much more effective.


----------



## Fibes (Feb 18, 2010)

Many times the EMF source is what's plugged into or connected to the wiring. 

As far as what wiring method works best to elliminate EMF's, it's not really a wiring type issue it's how the wiring is installed. Simply make sure there is current flow in both directions in order to negate it and that there are no currents flowing in conductors or conductive paths that it is not supposed to be flowing on.

IOW's, the short and simplified answer is, there should be a hot / hot, hot / neutral, or hot and switch leg in every cable or raceway and make sure there is no current leaking to a coax, LV cable shield, or anything else.


----------



## LAElectrician (Dec 8, 2009)

CraigV said:


> Shield the room with copper mesh. Did he/you shut off the main to determine how much EMF he's reading from other sources? In many cases the home wiring is not a significant contributor.
> 
> Don't forget to wear your best tinfoil hat. If you put some egg salad between the layers it's much more effective.


Well, of course the first thing to always check for is microwave beams coming in from the NSA satilites that are spying on him. 

But really, he has his own Gauss meter and it only reads "excessive EMT" on 10 specific receptacles in his house, and he wants to bring new wires to them. The question is, which wiring method is best to reduce the EMF footprint?


----------



## nervous (Nov 13, 2012)

The best way is to rip out the drywall, install 1/8" lead sheets and re-install the drywall. No one will ever know that he has anti EMF and martian spy barrier.:thumbsup:


----------



## nolabama (Oct 3, 2007)

Tin foil hat?


----------



## CraigV (May 12, 2011)

LAElectrician said:


> Well, of course the first thing to always check for is microwave beams coming in from the NSA satilites that are spying on him.
> 
> But really, he has his own Gauss meter and it only reads "excessive EMT" on 10 specific receptacles in his house, and he wants to bring new wires to them. The question is, which wiring method is best to reduce the EMF footprint?


The best thing to do is ensure those branch circuits are wired correctly, in other words, no neutral-to-ground contact, hot and neutral are no reversed, etc. If any of those circuits feed a 3-way switch circuit, be sure there is no single phase conductor not paired with a neutral in the same cable. In other words, solid wiring methods executed properly will result in "safe" wiring in all respects. Even "consultants" who specialize in low-EMF home wiring recommend this. If the house is wired properly, EMF should be very low.


----------



## Amish Electrician (Jan 2, 2010)

I had a guy pull a gauss meter on me once ..... silly fool!

You see, I have the Greenlee HID bulb tester. Push the 'test' button and every gauss meter for blocks will peg. I had him searching for the 'source' in his kitchen wastebasket in no time at all


----------



## Meadow (Jan 14, 2011)

Twist the current carrying THHN conducters and place them in EMT/heavy guage conduit with an indivdual ground conducter on the side. Switch both hot and neutral simatanously at the switches. Consider using an isolation transformer for the 120 volt system and a contacter to turn off the bedroom circuits if that is of concern. Dont run anything behind or under the bed frame areas. Run conduits as short as possible. 

Dont use twisted romex, its not worth it. Some MC even becomes pre twisted. 

I know theres more but its been a while since I did a low EMF house.


----------



## LAElectrician (Dec 8, 2009)

CraigV said:


> The best thing to do is ensure those branch circuits are wired correctly, in other words, no neutral-to-ground contact, hot and neutral are no reversed, etc.


You wrote "no neutral-to-ground contact", but the neutral will eventually be grounded at the main panel, right?


----------



## Fibes (Feb 18, 2010)

LAElectrician said:


> You wrote "no neutral-to-ground contact", but the neutral will eventually be grounded at the main panel, right?


 That is correct but that is the only place, after that you would be paralleling the neutral as far as current flow is concerned and this leads to non canceling currents


----------



## Dennis Alwon (May 9, 2009)

There are 3 basic causes for emf's in a home. NM cable is perfectly ok but if he has more than 2 mlligauss when the lights are on then there is an isssue.

1. neutral and egc are touching after the load 

2. Neutrals from one circuit are tied to neutrals from another circuit.-- I have found this in switch boxes where there are 2 feeds in a 3 gang box and all the neutrals tied together-- easy fix

3. If the circuit is run and the neutrals and hot conductors are not run together as IN knob and tube wiring and some 3 way installs.


----------



## LAElectrician (Dec 8, 2009)

Dennis Alwon said:


> 1. neutral and egc are touching after the load
> 
> 2. Neutrals from one circuit are tied to neutrals from another circuit.-- I have found this in switch boxes where there are 2 feeds in a 3 gang box and all the neutrals tied together-- easy fix


1. What does egc mean?

2. Is it OK to run a three wire circuit (two hots sharing one neutra)l, or do you think it's better to run a dedicated hot and neutral


----------



## Speedskater (Oct 2, 2009)

On shielding:

a] For low frequencies (power line), soft steel work's best.

b] For radio frequencies, copper or aluminum work's best. But aluminum is harder to make good joins & connections.

c] Lead is for X-rays and sound absorption. 

d] Ralph Morrison in his book "Grounding and Shielding: Circuits and Interference" on page 180 writes about building a screened room laboratory. 

e] Page 13 of this paper has some power line noise tests.

Integrating Electronic Equipment and Power into Rack Enclosures
Optimized Power Distribution and Grounding for Audio, Video and Electronic Systems

http://www.middleatlantic.com/pdf/PowerPaper.pdf

f] Twisting current carrying wire pairs is always good. The more twists per foot the higher the frequency, that it's good for.


----------



## Mshea (Jan 17, 2011)

I have to tell you all this story.

We have a local EC that sells a lot of power quality and loves to scare people with his Gauss meter. He extols the perils of magnetic fields and I think 90% of his business is related to EMF.

My story involves a young down to earth family in their first house. The have this EC do a EMF check on the house and as part of a whole house renovation decide to also rewire. The EC recommends AC-90 as the armour helps shielding. The house was Knob and tube so we did expect to see some EMF.

I am in the house doing a rough wire inspection and in speaking to the homeowner I notice she is wearing a haematite bracelet. This is a form of magnetic glass-like material. IE it looks like black glass but is metal. I ask her this. I see you are wearing a magnetic bracelet? Yes it helps with the bodies healing mechanisms. Oh how interesting. But you are spending an extra few hundred dollars to eliminate magnetic fields from your house? Isn't that contrary to the reason you are rewiring the house with BX instead of NMSC? Blank stare!

I pretty much dropped it there except to reassure her the wiring was some of the best I have seen from this ec and maybe they should always work with bx.

I did not want to get into an ac field versus steady fields or other stuff I don't believe. My other favourite story is the smart meter protester with a cell phone next to her head but that is another story :whistling2:


----------



## Dennis Alwon (May 9, 2009)

LAElectrician said:


> 1. What does egc mean?
> 
> 2. Is it OK to run a three wire circuit (two hots sharing one neutra)l, or do you think it's better to run a dedicated hot and neutral


EGC is equipment grounding conductor

Yes you can share a neutral but with afci breakers being required I would not do that.


----------



## LAElectrician (Dec 8, 2009)

Dennis Alwon said:


> EGC is equipment grounding conductor
> 
> Yes you can share a neutral but with afci breakers being required I would not do that.


Thanks for the info. And yes, since most EMF issues usually concern the living and sleeping areas of the house, AFACI dedicated circuits are almost always going to be used, but I was just wondering about three wire circuits and EMF.


----------



## ponyboy (Nov 18, 2012)

what in the f*** is EMF.


----------



## TOOL_5150 (Aug 27, 2007)

ponyboy said:


> what in the f*** is EMF.


you are a journeyman.. and dont know what EMF is.... wtf?


----------



## Cletis (Aug 20, 2010)

Ring Wiring


----------



## ponyboy (Nov 18, 2012)

TOOL_5150 said:


> you are a journeyman.. and dont know what EMF is.... wtf?


Its how you find ghosts and stuff right??


----------



## ponyboy (Nov 18, 2012)

TOOL_5150 said:


> you are a journeyman.. and dont know what EMF is.... wtf?


I got some snake oil I'd like to sell you


----------



## Keyrick (Nov 10, 2010)

EMF = Electro-Motive Force = Voltage

EMI = Electro-Magnetic Interference, which I believe is what the OP is trying to eliminate or subdue.

EMT = Electrical Metalic Tubing!

:whistling2:


----------



## Meadow (Jan 14, 2011)

LAElectrician said:


> Thanks for the info. And yes, since most EMF issues usually concern the living and sleeping areas of the house, AFACI dedicated circuits are almost always going to be used, but I was just wondering about three wire circuits and EMF.


 
Im not completely sure about this but I would think a shared neural would be fewer EMFs then compared to two seperate circuits. Both because 2 circuits are now in one race way or cable assembly and the fact that you are running all sources from the transformer. Ive been told that running both sources cancels static fields better because when one hot is at absolute positive the other is at absolute negative. 

Ive had EMF customers use that to justifie balanced power 60-0-60 volts in homes but thats another story. 

The question boils down to how much EMF reduction the customer wants.


----------



## chicken steve (Mar 22, 2011)

meadow said:


> The question boils down to how much EMF reduction the customer wants.


i suppose it depends on how much they pick up....








~CS~


----------



## Dennis Alwon (May 9, 2009)

ponyboy said:


> what in the f*** is EMF.


In this case electromagnetic fields or elevated magnetic fields


----------



## Meadow (Jan 14, 2011)

chicken steve said:


> i suppose it depends on how much they pick up....
> 
> 
> 
> ...


 :laughing:
As long as their willing to pay Im fine with what ever they want:thumbup:


----------



## Amish Electrician (Jan 2, 2010)

It's so hard to stay on-topic with EMF!

I know of one instance where a guy went out of his way to purchase a long, complex piece of property, only to build a house at the extreme corner where the property passed under some HV lines. He then went on an internet rampage about all the 'dangerous' EMF that was preventing him from using the house, etc.

Gee, do you think maybe the guy deliberately created his complaint? Think maybe he had an agenda?

Dennis, you might be right, in terms of using EMF to identify other issues. Yet, there's no way to say that any amount of EMF does anything bad; studies have been all over the map and unrepeatable. Call it what you will, but "science" requires repeatable, controlled experiments. The whole EMF debate argues data that is neither controlled nor repeatable.

Near me is an HV transmission line. I think it's somewhere around 150KV - this is long-distance PoCo to PoCo transmission, on poles that reach halfway to heaven. Big stuff. Every so often, on the 'bird guards,' there is an eagle's nest. Now, if EMF was half as bad as some claim, I'd expect those birds to fly backwards. It doesn't happen.

Meanwhile, every six months we get another "study" reported that asserts that cell phones are cooking our brains. 

I say ... if you're THAT worried, go "Amish."


----------



## user8640521 (Jan 17, 2009)

LAElectrician said:


> Hi guys,
> 
> I've got a customer who wants my company to re-wire some of his receptacles in his bedroom to lessen the amount of EMF he's picking up with his Gauss meter. I have no experience in this.
> 
> ...


you can purchase "shielded" romex that is round in
cross section, has stranded thhn conductors, and a
black filler material that is thermoplastic with a ferrous
shielding material added. (iron filings, i believe)

it is used mostly for structured cabling in high end A/V
installs, by people with more money and OCD.
(obsessive compulsive disorder, not an electrical term)

$1.20 a foot for 12-2 with ground.

if you are in possession of a affluent quackadoodle customer,
i'd suggest removing all the drywall, and installing
a faraday shield made of copper mesh, or better yet,
copper foil. if you use copper foil, be sure to solder all
the laps, using lead free solder.

drive ground rods, and cadweld 4/0 between them, then
bond the faraday shield to the 4/0.

now, put isolation transformers on all sources of power,
enclose the entire room in a box made of 1/4" steel plate,
weld all the laps on the steel box, put copper mesh faraday
shields across the air ducts going into the room.

for the door into the room, make sure there is copper mesh
where the door seals, and the door is 1/4" steel plate.

their are companies who make faraday panels to save having
to lap solder the foil under the sheetrock.

i've only worked on one room done like this. it's in calif. at
the edison LARS facility, and it's used to house the atomic
clock that synchronizes the power grid to the NIST master
reference clock in boulder colorado.

that clock is sensitive enough that it can detect 1/2"
of movement in it's receiving antenna that ties it to
the NIST master clock. it can accurately resolve
the time it takes for a RF wave to travel 1/2".

so, unless your customer has a watch that resolves
to seven places past the decimal point, they are
just a self absorbed narcissic yuppie with more
money than sense. fluff them well, and they will
pay for a semester of your child's college education.

by the way, a technician who can REALLY scan for
frequencies to 5 GHz, and accurately identify and
isolate those leakages, in 1988, went for $5,000
PER DAY, plus expenses.

we had a RF leak in the room to locate. took two days.


----------



## Meadow (Jan 14, 2011)

Amish Electrician said:


> It's so hard to stay on-topic with EMF!
> 
> I know of one instance where a guy went out of his way to purchase a long, complex piece of property, only to build a house at the extreme corner where the property passed under some HV lines. He then went on an internet rampage about all the 'dangerous' EMF that was preventing him from using the house, etc.
> 
> ...


 
It also has not been determined exactly why cancer is becoming so prevalent or why Schizophrenia exists in an estimated 1 in 100. Same with child hood Leukemia. There many things established that could cause these and certainly there could be other things responsible for them as well.

Food for thought, asbestos was once considered no more dangerous than sheetrock. Lead had no health effects. Same with cigarettes in the early 1900s. The list keeps growing.

Keep in mind that if electricity was proven to be a carcinogen, anybody living near power lines would be flipping.


----------



## CraigV (May 12, 2011)

meadow said:


> It also has not been determined exactly why cancer is becoming so prevalent or why Schizophrenia exists in an estimated 1 in 100. Same with child hood Leukemia. There many things established that could cause these and certainly there could be other things responsible for them as well.
> 
> Food for thought, asbestos was once considered no more dangerous than sheetrock. Lead had no health effects. Same with cigarettes in the early 1900s. The list keeps growing.
> 
> Keep in mind that if electricity was proven to be a carcinogen, anybody living near power lines would be flipping.


Yes, but asbestos, lead and cigarettes WERE found to be dangerous by scientific testing, not by simply declaring something that isn't understood "dangerous".


----------



## Wirenuting (Sep 12, 2010)

You get more EMF from your clock radio by the bedside then you so from premises wiring. 
And I'm not going to wear my tinfoil hat anymore.


----------



## uconduit (Jun 6, 2012)

ponyboy said:


> Its how you find ghosts and stuff right??


----------



## Dennis Alwon (May 9, 2009)

EMF's are only dangerous , by some studies, at 2mg however the distance from the emissions changes that. Sure sleeping with a heated blanket is not a good idea esp. for a pregnant women and there have been studies that state there is danger of childhood Leukemia when high mg levels are encountered for long periods. Stand by a microwave and read the emf's of that -- I did one and had 40 mg right next to the door but 0 a few feet away.

You can laugh and joke about it but I would not want my child living in a home with high emf's. Most of the time it is an easy fix esp. in new homes and AFCI will probably trip when at least 2 of the methods I mentioned are used.


----------



## Cletis (Aug 20, 2010)

ponyboy said:


> I got some snake oil I'd like to sell you


If you can't see it or tell it's there it can't be bad for you then right?


----------



## Big John (May 23, 2010)

CraigV said:


> Yes, but asbestos, lead and cigarettes WERE found to be dangerous by scientific testing, not by simply declaring something that isn't understood "dangerous".


 Very well said. 

If there were deleterious effects to EMFs we would be some of the first people to see it, because I'd bet our exposure levels are several times higher than the average joe. 

I think a Canadian utility even did a study on it's linemen looking for unusual health trends that may be related to high EMF exposure, and I don't believe they found anything significant, though I'll have to see if I can find the study.

-John


----------



## Meadow (Jan 14, 2011)

CraigV said:


> Yes, but asbestos, lead and cigarettes WERE found to be dangerous by scientific testing, not by simply declaring something that isn't understood "dangerous".


At one point those substances were under scientific testing as well before a conclusion was reached. Cigarette studys in the 60s said they were safe the others that did were scrutinized. Most of that was because cigarette companys did not want people to associate them with negative health.

EMF tests today for non-ionizing radiation is well under way. Some say yes some say no. Its still a battle. I have no clue myself either. With at least half saying theres a concern why take the risk? If it is dangerous you know your protected. If its not at least you know your system is above code. The other way around is more of a gamble.


----------



## TTW (Sep 14, 2012)

That settles it! I'm getting me one of these!


----------



## Wirenuting (Sep 12, 2010)

TTW said:


> That settles it! I'm getting me one of these!


I need one of these for global warming


----------



## brian john (Mar 11, 2007)

Is there a basement?

Run the branch circuit wiring low or in the basement ceiling vertical runs up to receptacles mounted low on the wall, a twisted cable may help so MC. Shielding is best with Mu Metal but a thick aluminum plate is 2nd best. But an effective shield can only be 100% workable if properly designed.


----------



## Wirenuting (Sep 12, 2010)

brian john said:


> Is there a basement?
> 
> Run the branch circuit wiring low or in the basement ceiling vertical runs up to receptacles mounted low on the wall, a twisted cable may help so MC. Shielding is best with Mu Metal but a thick aluminum plate is 2nd best. But an effective shield can only be 100% workable if properly designed.


Glad to see I'm not the only zombie thread victim.


----------



## brian john (Mar 11, 2007)

Wirenuting said:


> Glad to see I'm not the only zombie thread victim.


I never check the dates if a thread pops up and peaks my interest I hop on.


----------

