Re: Re: [eSens]

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Andrew McAfee

Re: Re: [eSens]

Excellent report Bill! I have experienced and trouble-shot the neutral wire
problem extensively in my homes. I have not heard about the ground loop
issue.
Thank you! I will forward this to my "current" electrician.
Andrew

>On Sat, 20 Jun 2009 21:36:17 -0600 Bill Bruno <[hidden email]> wrote.
>The ideal grounding system has one single point where everything is
>grounded,
>and ground wires never form a loop. People who care about interference
>know about this... especially sensitive electronic equipment.
>
>If the electric system ground is connected to the plumbing in two places,
>you have a ground
>loop. Since your neighbor's connection counts, you probably don't want any
>connection,
>but one is much better than two (and your electrician may insist, and
>legally should
>insist, on one... but it's not that hard to disconnect it yourself. A

more
>code
>compliant way is to get a plumber to add some plastic tubing or a
dielectric

>union. One should be careful not to hold both sides of where you're
>disconnecting
>and pull apart... if there is a large inductance and substantial current
>(usually it's
>tiny) you could die. When cutting a pipe, having a jumper wire across the
>cut
>and then pulling the wire off with one hand (or better, rubber glove or
>insulated pliers)
>ensures it's safe. Usually only an issue if you're cutting a water main
>which
>could carry lots of current, but in some cases your home ground wires could
>too.
>
>Note that a loose connection is even worse than a loop, so make sure you
>break
>the connection and secure so it doesn't go back.
>
>Also note that if your whole yard is at the same field level as the house,
>or there's
>a big power line, the effect of the ground loops may be too small to notice
>any
>improvement.
>
>Another kind of ground loop is when the ground wires for different circuits
>are connected
>behind say a light switch. This loop will tend to spread the field at the
>panel throughout
>the house. 240 volt appliances like dryers or stoves could also have a
>ground loop
>from tying the ground to neutral. But this is typically not so terrible
>because both wires
>stay in the same cable and so the loop area is small. But appliances

where
>water and
>gas lines meet the electrical system (dishwasher, refrigerator ice maker,
>stove, furnace)
>are very likely to create such loops. These days you can easily find vinyl
>hose connectors
>for a dishwasher which will isolate it from the water pipes. Same for an
>ice maker. For gas appliances, get
>a plumber who knows about gas dielectric unions. But first check that
there
>is current in the pipe
>near the appliance. Use a very sensitive Gauss meter, and see if the field
>gets a bit higher
>near the pipe. Actually I prefer to use a cheap "telephone listener" or
>buzz stick for this.
>You want something that can measure very close to the pipe. Be sure to try
>different
>orientations if you didn't study magnetic fields in physics class. This
is

>actually quite
>sensitive and the electrician's current meter won't detect it. If the loop
>is big a few milliamps
>is worth fixing (if there are no worse sources covering the area).
>
>I'm assuming you've already taken care of any crossed neutral wires. These
>are worse than
>ground loops. These are explained in Ed Leeper's book Silencing the
>Fields. If the field
>goes up in the whole room when you turn on a 3-way switch, you need to
>separate the
>neutrals for the different circuits. While you're at it separate the

ground

>wires too, and you've
>fixed a ground loop.
>
>In my house the worst ground loops were caused by new wires added and the
>ground
>connected loosely to the old ground wire.
>
>Walk around the house with a gauss meter, when the fridge and other motors
>are off,
>and try to figure out what's causing the hot spots. Sometimes fixing those
>will lower
>the field in whole house. I think I still have one or two ground loops,

but

>you can't
>even find the minor ones until the major ones are fixed.
>
>Bill
>
>
>On Sat, Jun 20, 2009 at 5:51 PM, laurel canyon <[hidden email]> wrote:
>
>>
>>
>> An electrician friend just came in and I asked him what ground loops were
>> and he did not know. Could someone explain what that they are? TIA
>>
>> --- On Sat, 20/6/09, laurel canyon

<[hidden email]<[hidden email]>>

>> wrote:
>>
>> From: laurel canyon <[hidden email] <[hidden email]>>
>> Subject: [eSens] "Removing ground loops"
>> To: [hidden email] <[hidden email]>
>> Received: Saturday, 20 June, 2009, 7:43 PM
>>
>>
>> Bill Bruno wrote:
>> My house was about .08 when I moved in. Removing ground loops got it to
>> > .03.
>>
>>
>>
>> What are ground loops and can any electrician remove them.. or anyone

else,

>> like myself?
>> \
>> TIA
>>
>> Laurel
>>
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>>
>>
>
>
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Andrew McAfee