[RE-wrenches] Odd Outback FNDC/Mate issue

[Richard L Ratico]

Joel,

Here's a "blast from the past".
http://lists.re-wrenches.org/htdig.cgi/re-wrenches-re-wrenches.org/2005/016854.h
tml

It's pasted in below:

Kelly,
When Richard Perez and I were doing measurements on EMF fields with 
our homemade Gaussmeters years ago, we found the largest source of 
EMF came from the inverter/Battery cables. Makes sense as there is 
some heavy amperage switching going on. Twisting the cables together 
helped some, but the best cure was distance. At a bit over six feet 
away from the cables, we were almost at background readings. The 
moral of that story is: Don't put the inverter under the bed, or if 
you must-put it at the foot rather than the head.
Allan S. is correct for the ac wiring as well. Twisting the 
conductors-but not the ground wire helped. Putting the whole shebang 
in EMT or metal flex really did the job.
Bob-O

>Hi all,
>
>Does anyone have experience in applying EMF mitigation
>to inverter installation?  Other than moving the
>inverter, are there other ways you've found to lessen
>or move the fields,  Maybe using shielding films or
>such?  And since those shields only affect magnetic
>fields, what about the remaining electrc fields? 
>
>Thank you all for sharing your experience!
>
>Kelly Larson

Regards,
Dick



--- You wrote:
Please correct me if I am wrong, but I thought that twisting wires creates a 
magnetic field and increases radio frequency interference.

----- Original Message ----- 
From: "Richard L Ratico" <Richard.L.Ratico at VALLEY.NET>
To: <re-wrenches at lists.re-wrenches.org>
Sent: Friday, March 27, 2009 6:28 AM
Subject: Re: [RE-wrenches] Odd Outback FNDC/Mate issue


> Howie,
>
> Very high, rapidly fluctuating, DC currents are carried by battery cables. 
> These
> produce powerful, local magnetic fields. Many sources recommend twisting 
> the
> cables together to reduce RFI. I have found this twisting hard to do well. 
> Steel
> conduit accomplishes the same thing, more effectively. Resist the 
> temptation to
> put any other wiring in that conduit. This would most likely be a code 
> violation
> in any case; wires of different voltage ratings in the same conduit are
> generally prohibited.
>
> Dick
--- end of quote ---