EMR-4000
IM02602009E
Setting Example: Analog Output with Power Factor PF*
*=only available in Devices that offer Power Protection
Since the sign of Power Factor PF follows the sign of Active Power P, there is no distinguish between capacitive and
inductive Reactive Power. Hence, for Analog Output assignment the setting for PF output range uses a Power Factor
with a “Sign Convention”:
a positive sign (+) PF, if Active and Reactive Power has same sign
a negative sign (-) PF, if Active and Reactive Power has different sign
For e.g. if Active Power is flowing into the load and Current lags the voltage for a inductive load, PF with sign
convention uses a positive sign. This is important to set the right range settings for Analog Ouput.
Use case for analog instrument with 4...20mA with linear scale, where scale is in range from 0.8 capacitive to 0.3
inductive, following setting should be uses:
Range min (0%) = -0.8
Range max (100%) = +0.3
Calculate the Analog Output percentage for specific value for e.g. unitiy: |PF|=1 at phi = 0°:
First the signed PF needs to be converted into a linear range:
Range min' (0%) = -1 – (-0.8) = -0.2
Range max' (100%) = +1 – (+0.3) = +0.7
InputValue' = +1 – (+1) = 0.0
AnalogOutput (InputValue') = 100% / (Range max' – Range min') * (InputValue' – Range min')
AnalogOutput( 0 ) = 100% / 0.9 * 0.2 = 22.2%
The Output current for e.g. 4...20mA type is then 7.5 mA = 4mA + 22.2% * (20mA – 4mA)
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