I think I have confirmed that the problem is the motor capacitor. I have connected a 47uF Bi-Polar Cap across the motor connections in the shack, which is effectively across the 100uF up at the motor (unless a limit switch opens), and all seems to be working in both directions now.
- Paul At 03:30 PM 12/10/2009, you wrote: >Thanks for your thoughts. > >The current is about 2A when stuck or moving. (Same in both directions) > >I can get it to move if I up the voltage a little >with a series transformer. Nominal voltage is >about 28V in the shack. By adding 10V it moves >fine. So temporarily I will add a series voltage >to "kick start" it, until the wx warms up and I can service the rotor. > >Regards > >- Paul KW7Y > > > >At 01:31 PM 12/10/2009, you wrote: > >Hi Paul, KW7Y > > > >I suppose that you measure: > > > >Between A6 and A4 for CCW = 4.4 ohm > >Between A6 and A5 for CW = 4.4 ohm > > > >I suggest you to put an AC ammeter 5 Amps f.s. in series between the > >common terminal A6 of the control box and the wire coming up to A6 > >in the motor. > > > >In this condition the AC current running CW or CCW must be about > >the same. > > > >If the current increases when the motor stuks in CW position then there > >is a mechanical problem inside the rotator. > > > >If the current is low when the motor stucks in CW position probably the > >capacitor C 35 losted capacity and if the current is zero probably the > >limit switch SW-7 inside the rotator is defective. > > > >Unfortunately if the AC capacitor C35 = 100 uF AC wich is connected > >between A4 and A5 inside the rotator losted capacity you cannot measure > >its capacity from the shack. > > > >The motor is a brusheless AC asyncronous motor using the starting > >capacitor C 35 to produce a 90° phase shift between both windings. > > > >73" de > > > >i8CVS Domenico > > > >----- Original Message ----- > >From: "Paul Baldock" <[email protected]> > >To: <[email protected]> > >Sent: Thursday, December 10, 2009 3:22 AM > >Subject: [amsat-bb] G-5500 problem > > > > > > > I have a G-5500 that sometimes will not turn clock wise(CW) but will > > > turn counter clockwise (CCW) OK. When it is working OK in both > > > directions each winding (CW and CCW) measures about 4.4 Ohms in the > > > shack. When it will not turn CW that winding measures about 2.2 ohms > > > (The CCW winding still measures 4.4 ohms). > > > > > > The Controller is fine, so the problem is in the motor. > > > > > > Does this motor have brushes? > > > > > > Any thoughts on what the problem might be? > > > > > > Thanks > > > > > > - Paul KW7Y > > > > > > _______________________________________________ > > > Sent via [email protected]. 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 > > >_______________________________________________ >Sent via [email protected]. 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 _______________________________________________ Sent via [email protected]. 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
