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Re: NEON- Re: Power factor & Load Current
tmjdorr wrote:
> So, following this, what I understand is that only the uncorrected power
> factor/standard type transformers are available in the US and we should clearly
> be using the table for "Uncorrected." Right?
REPLY FROM DIRK: FIRST QUESTION TO TDI.
Is the above trye Telford? What a waste of enrgy! What about the
environmental aspect about this. If you convert the above to mercury you
are wasting hundreds of kilo's of merc. What about that?
> If so, I was also wondering why we aren't using those with a corrected power
> factor. I recall seeing the capacitors that were added to transformers in The
> Netherlands and I think I'm finally starting to understand the concept. Or am
> I?
No dear Tom, you are not. On the contrary, saving energy is intelligent,
and social people are doing that all the time. I know that you don't
have that "who cares" mentality and that's good for you, for us and the
environment.
>
> Tom,
>
> It does seem like (and is) a never-ending quest to understand these things.
> Maybe I can help. When we refer to 'power-corrected' transformers, we are
> refering to transformers which contain a capacitor to compensate for the
> transformer's natural inductive characteristics, as seen by the power lines.
> These are also called "high power factor" transformers.
>
> Note: "strayfield" (European term) is the regular everyday magnetic type of
> transformers we normally use, and they come both power factor uncorrected and
> corrected.
>
> The deal is this: uncorrected transformers draw more line current than a
> corrected type, because the line must supply power for the neon load
> ("resistive") AND power to the transformer's uncompensated inductance
> ("reactive"). The reactive power is returned back to the line [which pisses off
> the power company people because almost all losses associated with reactive
> power occur on their side of the meter). This is why transformers are rated in
> 'volt-amps' (VA) rather than 'watts' - VA includes the reactive power.
>
> The bottom line is this: the fuse (or circuit breaker) doesn't care a wit about
> whether the power is reactive or resistive - all it knows is AMPS. When we size
> fuses, therefore, we need to take into account any reacitve power circulating
> through our transformer, if it's uncompensated (not high power factor). The
> easiest way to do this is to divide the volt-amp rating, from the transformer's
> rating plate, by the nominal line voltage (120) to get amps; add whatever
> savety factor you normally use, and select fuses accordingly [amps = va /
> volts].
>
> They do sell power factor corrected transformers here (for an extra charge, of
> course, which is the primary reason they aren't used in all non-dimming cases),
> and are probably worthwhile on large installations to minimize line current (and
> are probably required by local code or by power company demands - see comments
> above).
>
> Hope this helps.
>
> Regards,
>
> Telford Dorr
Reply from dirk to Telford:
If this not helps nothing will helps. Nice reply TD. Pleas make another
one ( you know me I am asking not ordering) explaing the real power (the
WATT power) is almost halve of the consumption of the VA (seemingly)
power and therefor a contribution to the environment.
References: