Art. 300.3

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Dennis Alwon said:
It does not look like that...:D They are folded on top of each other but sure at some point they are a bit apart. I am surprised that would give off that much electromagnetic field's outside the box. Certainly inside the box there would be a reading as there are in almost all of them. Maybe that's doing it--- I will certainly find out here in the next week or so.
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Did you turn the circuit off and measure?

Are you expecting a zero reading?
 
jxofaltrds said:
Did you turn the circuit off and measure?

Are you expecting a zero reading?
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Of course it is zero with the circuit off. The kitchen had a 3 way where the neutrals were tied to other neutrals of the same circuit which gave 2 paths for the current to flow. Turn the lights off zero turn them on and we got about 12mg. Changed the connection- zero.
 
The worst problem in the house is the furnace transformer in the crawlspace. At the unit it puts out about 153 mg -- furnace not running-and even in the room above we get readings of 6-8 mg at 4' off the floor. Now she wants us to move the transformer to a remote area down near the crawl space floor. Guess I'll get an inline fuse and move it-- pipe it all the way
 
PS I have never seen a reading over 134 in a home and that was at the meter and the panel itself.

50-55mg was the highest and one of the biggest problems was the GEC attached, like in the old days, on the cold water line by the panel and not with the 5'. Knob and tube was in this home. And tons of ground conductors tied together.
 
Dennis Alwon said:
Brand new-- about 6 months
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Holly Molly.

What do you mean by furnace transformer?

Is there CSST in the home? Could there be a problem with the 'additional' bonding?

My old home. These are the big lines (about 600' away from home) and the reading at my front door was only 1.5mg. Directly under the lines 22-24mg.

I can't imagine a reading 4+ in the new home in only one area.

old.JPG
 
jxofaltrds said:
Holly Molly.

What do you mean by furnace transformer?

Is there CSST in the home? Could there be a problem with the 'additional' bonding?

My old home. These are the big lines (about 600' away from home) and the reading at my front door was only 1.5mg. Directly under the lines 22-24mg.

I can't imagine a reading 4+ in the new home in only one area.
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There is a transformer in the furnace that converts 240v to 24V or 12v-- I think 24V but anyway it is part of the unit. My furnace reads about 18 mg right at the unit but at a few inches away it is zero.


The csst is bonded properly and the house is not that big.
 
What was the initial problem that brought this situation up ? It says a lot that the home owner is having you fix this instead of the original EC, being the home is only six months old.
 
John120/240 said:
What was the initial problem that brought this situation up ? It says a lot that the home owner is having you fix this instead of the original EC, being the home is only six months old.
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Well the woman of the house is chemically sensitive and apparently had to have the WI-FI removed from the home because she was shaken from it. The ec was told about electromagnetic field's but apparently didn't follow thru assuming that a standard wiring job would be adequate. Well the home owner bought a gaussmeter and walks around the entire house checking out all areas. She and the ec's worker had a major falling out so she will not let him back.

I told her I didn't understand and could not comprehend what she feels because I cannot but that I could get rid of the fields. Unfortunately she does not understand that it is normal to have fields up against loads like switches etc.

We will be wiring a home theater on another job and the engineer wants mc cable run to all points in the room. Apparently a small field of any sort can affect the equipment in there. It's voodoo to me. :D
 
Apparently the smart meter from the power company is sending radio waves thru the home also. She is trying to get that removed-- good luck there.
 
Dennis Alwon said:
It does not look like that...:D They are folded on top of each other but sure at some point they are a bit apart. I am surprised that would give off that much electromagnetic field's outside the box. Certainly inside the box there would be a reading as there are in almost all of them. Maybe that's doing it--- I will certainly find out here in the next week or so.
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I know it doesn't look like that... ;) ...it's only meant to be representative.

Being a bit apart has a bit to do with it... but also being a bit together does, too. Where arrows are opposing direction and in near proximity, fields cancel. Where none oppose, no cancellation...

4-way3.gif
 
Smart I get it but you should get a field in just about every jb if there is a load. Every switch we tested that had a significant load had some electromagnetic field's but as I have said the field disappears when the meter is moved from touching the switch plate. This particular one does not. I guess the small separation in the box may be the culprit but I am not sure there is a way to rectify that. I will try that otherwise I will run a new 14/2 and change the connections in the 3 way that was a dead end.

BTW- now the doorbell trany is a problem. She is using that meter like those guys at the beach with metal detectors. Sometimes a little knowledge is dangerous.
 
Dennis Alwon said:
Smart I get it but you should get a field in just about every jb if there is a load. Every switch we tested that had a significant load had some electromagnetic field's but as I have said the field disappears when the meter is moved from touching the switch plate. This particular one does not. I guess the small separation in the box may be the culprit but I am not sure there is a way to rectify that. I will try that otherwise I will run a new 14/2 and change the connections in the 3 way that was a dead end.

BTW- now the doorbell trany is a problem. She is using that meter like those guys at the beach with metal detectors. Sometimes a little knowledge is dangerous.
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Tell her to put it next to the meter outside and watch her flip. If you are 'on' top of something yes you will get high numbers.

You could have her provide this service for others. You may never have to look for work again. :lol:
 
jxofaltrds said:
If you are 'on' top of something yes you will get high numbers.
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Yes, I know that but she does not seem to get it. Why does this small amount of electromagnetic field bother her but the stereo which puts out 10x that does not seem to be an issue-- I don't get it. Oh well if she wants to spend money we can do that but I don't like that situation.
 
Dennis Alwon said:
... This particular one does not. I guess the small separation in the box may be the culprit but I am not sure there is a way to rectify that. I will try that otherwise I will run a new 14/2 and change the connections in the 3 way that was a dead end.

...
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The only other thing I can think of is the switch contacts are arcing... not major arcing, just micro-arcs, like you'd get with micro-pitted contacts. Of course major arcing would show up too. ;)
 
Smart $ said:
Where's it located with respect to where she's measuring?

Is it a shielded type?
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The trany is in the crawl space probably in a 4" sq box mounted on the floor joist. The trany is just a standard bell type with unshielded 20/2 bell wire or t-stat type wire-- my guess anyway.


XFMR_001_image.jpg
 
Dennis Alwon said:
I don't understand how the hot wire and switch leg cancel as there is power going there and the neutral is in another cable away from it. .
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Because the current is going in opposite directions it cancels out.


For proof put an amp clamp around the two conductors running to a switch.
 
iwire said:
Because the current is going in opposite directions it cancels out.


For proof put an amp clamp around the two conductors running to a switch.
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Yes I get it now- for some reason I thought it had to be a neutral to cancel it out but it makes sense- doh.
 
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