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Re: Watt meters



Original poster: Jim Lux <jimlux-at-earthlink-dot-net> 

At 08:08 AM 3/15/2004 -0700, you wrote:
>Original poster: Yurtle Turtle <yurtle_t-at-yahoo-dot-com>
>I have two residential electric (energy) meters. These
>are the ones that are used to calculate my power bill.
>I assume these can be used with a stop watch to
>calculate KW? How do they calculate PF?


They don't calculate or measure PF.. they measure (only) active power.  You 
could measure the apparent power (combination of active and reactive power) 
with a RMS voltmeter and RMS ammeter and then calculate the PF from PF= 
(active power)/(apparent power)


>Do they assume
>a certain inductive load? For inductive load, a normal
>house normally only has HVAC, Refrigerator/Freezer,
>and Washer/Dryer. Garage door openers, etc. are
>probably insignificant.
>
>Adam