[amsat-bb] Re: Motor for Yaesu G5500 Azimuth Rotator?
domenico.i8cvs at tin.it
Sat Feb 25 06:11:33 PST 2012
----- Original Message -----
From: "Phil Karn" <karn at ka9q.net>
To: "Tim Cunningham" <n8deu at att.net>
Cc: "'AMSAT BB'" <amsat-bb at amsat.org>
Sent: Saturday, February 25, 2012 1:26 AM
Subject: [amsat-bb] Re: Motor for Yaesu G5500 Azimuth Rotator?
> On 2/23/12 2:51 PM, Tim Cunningham wrote:
> > I have rewound a few of these motor coils and a #24 to #26 gauge enamel
> > wire should work. A #22 gauge enamel wire would be too large and you
> > would not be able to wind the same number of turns.
> > It is the breakdown of the enamel due to wire heating that makes them
> > fail by creating a short circuit in the windings.
> I don't remember the wire size I used (it's been over 20 years) but
> you're right about the short circuit. Just one shorted turn will form
> the shorted secondary of a transformer, and the I^2R losses in that turn
> will create quite a bit of heat that will further damage the insulation
> on the nearby windings until the whole thing is toast.
Hi Phil, KA9Q
To prevent short circuits between turns of the windwing is suffice to
use # 24 fiber glass copper insulated wire for class H insulation
motors or transformers wich windstand constantly very high temperature
around 180° C, Celsius i.e. 356 ° Fahrenheit.
I have used it with success in critical applications to rewind DC
and AC motors working near steel melting fornaces for a Company
in Italy 50% with the USS Steel in Pittsburgh Pennsylvania.
More information about the AMSAT-BB