Subject:  Re EMF-L HARMONICS--TECH AND NONTECH
Date:     Wed, 9 Jul 1997 054627 -0500 (CDT)
From:     Clas Tegenfeldt <tegen@bemi.se>
To:       Multiple recipients of list <emf-l@mail.llion.org>
--------------------------------------------------

At 09:04 1997-06-17 -0500, you wrote:
>Karl Riley wrote:
>> However, since harmonics produce more neutral current than 60 Hz,
>> wherever there is a shunting of neutral due to wiring error or
>> grounding practices, there will be more neutral available to cause
>> higher net current magnetic fields. These may be the effects you have
>> been seeing.

>Patrick Lindahl wrote:
>I'm of the opinion that harmonics is not due to wiring error or
>grounding practice, but to all the electronics connected to the net. All
>electronic equipment generates harmonics, not only the 3rd harmonics but
>5th, 7th, 9th .... 21th and so on. These harmonics are not cancelled
>anywhere and are reflected back to the power plant. In fact, this has

All non-linear power drainage creates harmonics, and that is pure
mathematics!

So Patrick is right, we have harmonics of all kinds on our power system due
to modern electronics, fluorescent tubes, thyristors etc.
But Patrick, you are wrong on the account that the harmonics do not cancel
out, at the same time Karl also is wrong saying they do! How come?

If we have only one phase they will NOT cancel out.

If we have a balanced three phase system the fundamental 50Hz will cancel,
as will 100Hz, 200Hz, 250Hz, 300Hz, etc. But NOT 150Hz or 450Hz!
This is plainly and painly seen in practice on our distribution networks.

Every /third odd/ harmonic will NOT cancel out even in a perfectly balanced
three phase system.

Clas Tegenfeldt       ,,,
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