GE EPM 5200 Benutzerhandbuch

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CHAPTER 1: AC POWER MEASUREMENT
CONSUMPTION, DEMAND AND POOR POWER FACTOR
EPM 5300 SERIES ADVANCED POWER METERS – INSTRUCTION MANUAL
1–5
1.3
Consumption, Demand and Poor Power Factor
CONSUMPTION
     
W = instantaneous power   T = time in hours
The total electric energy usage over a time period is the consumption of WH.  
Typically, the unit in which consumption is specified is the kilowatt-hour (KWH): one 
thousand watts consumed over one hour. Utilities use the WH equation to determine the 
overall consumption in a billing period.
DEMAND: Average energy consumed over a specified time interval. The utility determines 
the interval, typically 15 or 30 minutes. The utility measures the maximum demand over a 
billing period. This measurement exhibits a deviation from average consumption, causing 
the utility to provide generating capacity to satisfy a high maximum consumption demand. 
The highest average demand is retained in the metering system until the demand level is 
reset.
POOR POWER FACTOR: Results in reactive power consumption. Transferring reactive 
power over a distribution network causes energy loss. To force consumers to correct their 
Power Factor, utilities monitor reactive power consumption and penalize the user for Poor 
Power Factor.
T
 
 W
=
WH
×