> Assuming the motor can take it, motors with start/run windings can be
> damaged when operated at low voltage, the only problem is instability
> in the fan speed.
>
> A fan motor will wander around in speed a large amount with slight
> changes in temperature and pressure when operated at greatly reduced
> voltage, and might not always start.
>
> //That's basically been my experience, as well. Although small fan
> motors, typically only about 12/100ths of a horsepower, are used in
> cooling ham gear and probably won't overheat when used at reduced voltage,
> the counter emf produced by the fan as it rotates continuously tries to
> stop the motor, so that must be overcome by the application of more emf.
> There's a critical threshold where the fan falls into the twilight zone
> and may rotate but provides no pressure at all. While we as amateur
> experimenters may choose to operate near that threshold, I don't think
> commercial enterprises should, it's risky. The fan manufacturers normally
> don't rate their fans or blowers to operate at substantially reduced
> voltage. -WB2WIK/6
>
>
>
>
>
>
>
>
> 73, Tom W8JI
> W8JI@contesting.com
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