Good point! Yes some (not all, probably just on newer models) NST's have
PFC caps built in to them, and they're just fine to use - saves you the
trouble of adding your own external cap. An NST with a built-in PFC cap
will indicate something like "H PF" on the label, indicating a high power
factor. I don't know how you'd measure that though and I don't know if the
internal cap is as high as might be optimum..
Regards, Gary Lau
MA, USA
On Sat, Apr 25, 2015 at 2:25 PM, Carl Noggle <cn8@xxxxxxx> wrote:
> Hey---
>
> NSTs have PF correcting caps in them already. It sounds like they are not
> right for correcting for a TC. (No surprise there.) Is there information
> on this? Is there an easy way to measure PF? Does it sometimes require a
> lagging correction (inductive)?
>
> Carl
>
>
>
>
>
>
> On 4/24/2015 7:52 PM, Gary Lau wrote:
>
>> Hi,
>>
>> I think either cap series is acceptable - this is a very non-critical
>> application, given the relatively short run-times involved. It's not like
>> it on a rooftop in an air conditioning unit running 24/7. But I think the
>> 25uF value is too low; for a 15/30 NST at 120VAC/60Hz you want something
>> like 120uF. For 240/50 it's less, not sure how much. But again, this is
>> a
>> fuzzy target - there's not a sharp sweet-spot.
>>
>> For line filters, I think most folks just use whatever they find on the
>> surplus market. I put up a web page about how to hook up EMI filters - it
>> may not be obvious in which direction to hook them up! See
>> http://www.laushaus.com/tesla/emifilter.htm
>>
>> Regards, Gary Lau
>> MA, USA
>>
>>
>> On Fri, Apr 24, 2015 at 3:08 PM, Ayush Sharma <ayushsharma3210@xxxxxxxxx>
>> wrote:
>>
>> Hey
>>>
>>> Thanks to all the people helping out in my previous queries. Here's
>>> another
>>> question out to all you folks.
>>> While searching for a PFC Capacitor for my SGTC (15kV, 30mA) of rating
>>> around 25uF, I am confused about whether it is acceptable to use motor
>>> run
>>> capacitors made by companies like EPCOS listed here (
>>>
>>>
>>> http://en.tdk.eu/tdk-en/529468/products/product-catalog/film-capacitors/ac-film-capacitors
>>> ) or focus on the dedicated Power Factor Correction capacitors made by
>>> them
>>> listed here (
>>>
>>>
>>> http://en.tdk.eu/tdk-en/530264/products/product-catalog/components-for-power-factor-correction/phasecap--premium-capacitors
>>> ).
>>>
>>> I am able to procure the AC film capacitors (for motor run) pretty easily
>>> in local shops, but am having a hard time locating the other type.
>>> Has anybody previously used the EPCOS B323 seris of Motor run capacitors
>>> successfully?
>>>
>>> Also, on a related note, any suggestions as to what kind of a Line Filter
>>> should i be looking at (Power supply is 240Volts, 50Hz).
>>>
>>> Regards
>>> Ayush Sharma
>>> ᐧ
>>> _______________________________________________
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>>>
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>> http://www.pupman.com/mailman/listinfo/tesla
>>
>
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