Subject: High EMF in home (Mouscher)(Kingsbury)(Tegenfeldt)..
Date: Mon, 6 Dec 1999 044014 -0600 (CST)
From: "Roy L. Beavers"
To: emfguru
--------------------------------------------------
---------- Forwarded message ----------
Date: Mon, 06 Dec 1999 10:52:57 +0100
From: Clas Tegenfeldt
To: "Roy L. Beavers"
Cc: dm@mcs.net
Subject: Re: High EMF in home (Mouscher)(Kingsbury).. (fwd)
At 20:39 1999-12-05 -0600, you wrote:
>---------- Forwarded message ----------
>Date: Sun, 05 Dec 1999 18:30:01 -0500
>From: Bill Kingsbury
>To: "Roy L. Beavers" , Dean Mouscher
>Subject: Re: High EMF in home (Mouscher)..
>
>Dean Mouscher wrote:
>> I have found quite high ambient EMF fields in my home --
>> as high as 35-50 milligauss in one room - highest at the
>> floor and progressively less as you go higher. It seems to
>> be centered around the cold water main right under the floor.
>
>This problem may be caused by a short circuit in an electric
>water heater, pool or spa heater, ice cube maker, etc.
>
>Or, something that is 'grounded' to the water pipe is actually
>'hot' -- check all wires attached to water main grounding clamps
>for current flows. The ground wire could be from an antenna
>with a AC powered rotator, or a telephone or cable box, etc.
I have to protest against this! Of course there is a slight possibility
that an electric fault is at hand, but it is VERY seldom the case.
Most, if not all, ground currents are NOT caused by any fault at all
but by simple physics laws and the basic construction of the
electric system in many countries.
If the hot wire would be in contact with the water pipe, one of
two conditions would appear:
1 - the water pipe is not connected
to earth at all, therefore it will be at the same potential as
the live wire and as "hot". It would be a VERY dangerous situation BUT
there would NOT flow any current (as defined) and NO magnetic field
would result, this is CLEARLY NOT the case here.
2 - the water pipe is in fact connected somewhere to electric ground/earth
and therefore the potential will be very low (near ground potential),
current will flow. HOWEVER, since this situation: hot wire directly
connected to ground is a perfect definition of a shortcircuit, current
will flow without restrictions until the fuse blows. This will take
less than a second... This is also clearly not the case here.
So, the live/hot wire is NOT connected to the pipe. Simple deduction.
What really happens is that the current on the return wire gets to
a point where the neutral is connected to protective earth wire, this
is quite intentionally specified in the code books for many countrie's
electric systems. Then the protective earth (PE) is connected to the
enclosures of pumps, dishwashers, owens, stoves, heaters, etc.; anything
with a metallic case is normally connected to PE. Thus we have a
natural and correct current pathway through return wire to PE to
plumbing or other structural elements in buildings. It is NOT a faul,
it is a designed side-effect! (The electric system is not a tree structure,
it is a multipath graph...)
This is certainly true for sweden as well as many other countries,
including the US.
In some countries this is worse than in others, in the US the code
stipulates (has done so anyway) the use of plumbing as PE. The US
is worse of than sweden since the US uses a lower voltage and thus
higher current, creating higher magnetic fields. For the same situation
the resulting fields in an american home may be twice as high as
if the voltage had been 220/230 V instead of 110/115 V.
So, when high magnetic fields occur, do NOT hunt for electric faults.
Making an galvanic isolation of the water/gas pipes are the primary
and best solution. There are other ways to reduce or solve the problem
but maybe too technical for this forum.
Clas Tegenfeldt ,,,
(o o)
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Reprinted with permission of Roy Beavers, http://www.emfguru.com