[GreenKeys] Sync motor problems, again

[Bruce Gentry]

On 9/10/12 2:57 PM, John Nagle wrote:
>    I'm having problems with a Teletype GE sync motor again.
> Sometimes, when cold, it won't start, but hums and vibrates
> A push will get it going, so it's definitely the starting switch.
>
>    Will stuck Teletype sync motors overheat?  Modern motors
> have overtemp switches, but I doubt that these do.
>
>    Someone had a sync motor for sale.  If it's still available,
> let me know. Thanks.
>
> 				John Nagle
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Some of these motors have a centrifugal switch, and others have a 
voltage or current sensing relay to switch from start to run. If the 
motor has a starting condenser and it is failing, start torque will be 
low. The synchronous motors defiantly run hotter, and may not be 
equipped with thermal overloads. Overcurrent protection in equipment 
such as model 28s was more likely intended to prevent the machine from 
starting a fire rather than protecting the motor.

      Bruce Gentry KA2IVY