[Amps] fan experts

peter.voelpel df3kv at t-online.de
Sun Jan 29 15:20:29 EST 2006


They are capacitor-run motors,
What should be a reason not to use the variac?
The capacitor just shifts the phase.

73
Peter

-----Original Message-----
From: R. Measures [mailto:r at somis.org] 
Sent: Sonntag, 29. Januar 2006 21:03
To: peter.voelpel
Cc: 'Mike Bondarev'; Amps at contesting.com
Subject: Re: [Amps] fan experts


On Jan 29, 2006, at 6:43 AM, peter.voelpel wrote:

> Rich,
>
> Variacs are offered as option by EBM and Gebhard, the other large
> manufactur, especially for that reason:
> have the speed fully adjustable from zero to 100%.
> Look at the application in EBM catalogue Nr.2
> I hope there engineers know what they are doing ;-)).
> So far I never had any problem anyway.
>

With a shaded pole motor, lowered V is okay, with a capacitor-run 
motor, it isn't.
> 73
> Peter
>
>
>
>
> -----Original Message-----
> From: R. Measures [mailto:r at somis.org]
>
>
> On Jan 29, 2006, at 5:40 AM, peter.voelpel wrote:
>
>> I use those EBM blowers with my amps for 30 years, I never had 
>> Problem.
>> I select them much larger then necessary and use a variac to reduce 
>> the
>> speed, they are extremely quiet then.
>
> Reducing the voltage supplied to a capacitor-run AC motor is not good
> engineering practice.
>
>
>

Richard L. Measures, AG6K, 805.386.3734.  www.somis.org



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