[PRCo] Re: More Thoughts on 1600s versus 1700s

[John Swindler]

>Fred Schneider mentioned:
>
>.........
>
>The cars with blown motors probably could be made peppier than those with 
>internally vented motors, because the external fan on the MG set could keep 
>the motors cooler at lower speeds.  But I have never seen any proof that 
>specs for the limit relays were changed on cars with blown motors.  Now I 
>know I'm speaking Greek, right?


How do you say it, Fred:  damifIkno??

However, why would the operating characteristics of an electric motor differ 
with temperature?????  Isn't the ventilation needed to keep the motor from 
overheating to point where insulation fails and motor self-destructs??  
However, a gas motor does seem to run better after it has 'warmed up'.

Any electrical engineers available???

John


The motors on the original PCCs (and on most streetcars before
>them) were cooled by a fan on the armature in the motor.  Of course the fan 
>runs
>fastest when the motor run's fastest.  And the greatest heat is generated 
>when
>the motor is revolving very slowly.  Fineview was very abusive to such a 
>car.
>Blown is synonymous with extenerally vented -- those cars with blown motors
>required a separate fan on the MG set just to cool motors.  The distinction 
>was
>generally air-cars were internally vented and all-electrics had externally 
>vented
>motors.
>
>Jim Holland wrote:
>
> > Ken:
> >
> >         Interesting thoughts.
> >
> >         The 1600-series Interurbans saw even less usage than Any Other
> > PCC!    Relegated to strictly rush hour service post-1953 and with
> > 25-All-Electric Interurbans, this allowed complete base service on
> > both Charleroi and Washington while allowing for 6-9--spares of
> > All-Electrics!
>-- Trailing quotes stripped by Listar --
>
>


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