----- Original Message ----- From: "Phil Karn" <k...@ka9q.net> To: "Tim Cunningham" <n8...@att.net> Cc: "'AMSAT BB'" <amsat-bb@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. 73" de i8CVS Domenico _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
