Rockwell Automation 1420 PowerMonitor 500 - Manual (Page 33)

Rockwell Automation Publication 1420-UM001D-EN-P - September 2013
33
Unit Configuration
Chapter 3
Analog Output Configuration
Examples
These examples apply to units with catalog numbers 1420-V1A and 1420-V2A.
Example 1: Power value retransmission by means of a 0…20 mA analog output.
This example describes how to retransmit measured consumed power up to
100 kW by means of a 4…20 mA signal. Program the unit as follows:
• VARIABLE: W  (system real power)
• MIN OUT: 20.0% means 4 mA. The calculation to be carried out is the
following:
(100*minimum output) / full scale output =100*4 mA/ 20 mA=20%
• MAX OUT: 100.0% means 20 mA. The calculation to be carried out is:
(100*maximum output)/full scale output = 100*20 mA/20 mA= 100
• MIN INPUT: 0.0 k; the multiplier k, M, G can be selected on the unit
according to the chosen VT and CT values
• MAX INPUT: 100.0 k; the k, M, G multipliers can be selected on the unit
according to the selected VT and CT values
Example 2: Retransmission of the power factor (PF) value by means of the
0…20 mA analog output.
In this example, the unit is set up to retransmit the whole range of the allowed
values for the PF with a signal from 0…20 mA. The value of the PF variable can
vary between C0.001 and L0.000 (for each phase); these values, when
retransmitted, correspond to 0 and 20 mA. When the PF value is equal to 1, the
analog output value corresponds to the middle of the scale,
that is 10 mA. Program the instrument as follows:
• VARIABLE: PF L1 (or L2 or L3 or PF  )
• MIN OUT: 0.0%
• MAX OUT: 100.0%
• MIN INPUT: C0.001 (the C symbol shows a CAPACITIVE value)
• MAX INPUT: L0.001 (the L symbol shows an INDUCTIVE value).
L0.001 has been chosen as minimum value to be set to avoid undesirable
rapid changing of the outputs