Re: Watt meters

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: dave pierson <davep-at-quik-dot-com> 



>Is this true?

    Yes.

>   I thought that the electric meter just logged volts * amps *

    The mechanical arrangement of the voltage and current coils
    is set to measure 'real' KW.


>hours (really a KVAH meter)

    Implicit in the arrangement of the coils is that
    KVA (strict definition) will read low, its the 'real'
    power/energy being logged/recorded.


 > > but residential customers are not; they are
 >> charged purely on the basis of actual watthours.
    Nearly.  My understanding is they:
      measure actual KWH
        include an average PF (near unity) in the rate structure
          do the billing /rate math on the 'near unity' case.

    As noted, home loads are essentially unity.

    (motors are near unity, unless lightly loaded.)

best
    dwp