Doug, Mike and others,
Capacitors in and of themselves do not normally cause a problem. However,
at the distribution voltage level a "capacitor bank" is subject to a higher
degree of possibility of being an RF noise source. The associated
equipment, such as fused cutouts, oil switches, lightning arresters and
grounded equipment racks can all be a source of RF noise when they fail to
do their job properly.
At distribution voltages the capacitor banks are normally found out on the
line near the center of a load area requiring power factor correction. At
times they will be located right at a large industrial complex where large
quantities of motors (inductors) require correction of the power factor.
These banks are usually relatively small
At T-line voltage levels the capacitor banks will be relatively large
----- Original Message -----
From: "Michael Tope" <W4EF@dellroy.com>
To: "Doug Waller" <NX4D@comcast.net>; <rfi@contesting.com>;
<topband@contesting.com>
Sent: Monday, February 16, 2004 11:06 PM
Subject: Re: Topband: Local noise environment
> From: "Doug Waller" <NX4D@comcast.net>
>
> > At Buzz City, Florida, a 50 kVa line passes within one half mile of the
> > house. When the summer air conditioner season begins, the power company
> > throws in a capacitor bank, which corrects the power factor. These
> > capacitors, which look like large transformers with several cooling fins
> and
> > only one wire out the top, generate a plethora of harmonics and nasty
> > noises. The background noise level is raised 5 dB or so on 160m, but
> > listening to it on AM does not reveal a power hum, but more of a frying
> > sound.
>
> Doug,
>
> What is it about those capacitors banks that generates so
> much noise? In principle I would think that a capacitor wouldn't
> generate any extra noise unless there was some arcing going on
> in there, or am I missing something fundamental?
>
> Thanks,
>
> Mike, W4EF............................
>
>
>
> _______________________________________________
> Topband mailing list
> Topband@contesting.com
> http://lists.contesting.com/mailman/listinfo/topband
>
>
_______________________________________________
Topband mailing list
Topband@contesting.com
http://lists.contesting.com/mailman/listinfo/topband
|