Question about AC, frequency, and watts. - Page 2

  wrote:

Actually, it's 'average', not 'RMS'.  RMS power is a useless quantity.
RMS is applicable to voltage & current, but not power.

Paul Cardinale

 On Thu, 4 Jun 2009 11:49:40 -0700 (PDT), pcardinale@volcanomail.com
wrote:


Not to disagree with the point you're trying to make, but as an aside,
RMS power can be used to describe temperature rise situations
such as motor duty cycle.

dave y.

 
You are right, but this is a specialized application involved in application
of motors to cyclic loads and the definition is clear to those dealing with
this situation or similar situations where temperature is  the critical
limiting factor.

 However, somehow, the error that has crept in is that many refer to V*I
(*power factor) where V and I are rms quantities,as rms power which is
nonsense (i.e. Zzbun's statement) Unfortunately this error is quite  common
and reflects a lack of basic understanding . - it is this that Paul is
correctly addressing.


--
Don Kelly
dhky@shawcross.ca
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  But, people like me have actually worked on high voltage, rather
than
  with GE imbeciles, usually tell physicist to fuck off anyway so it
  doesn't matter.

 
  But, people like me have actually worked on high voltage, rather
than
  with GE imbeciles, usually tell physicist to fuck off anyway so it
  doesn't matter.

And who is the physicist? Not me,and the highest voltage that I have played
with was only in the order of 300KV
If youir statement was RMS power as a result of RMS voltage and current then
it is fundamentally wrong.  Common usage maybe -for audio salesmen, not for
technicians and engineers in the power industry who should know better.

If I have attributed this to you in error, then I apologise.

--
Don Kelly
dhky@shawcross.ca
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