Rockwell Automation 1405-M620 Operating Instructions - Manual (Page 6)

Publication 1405-IN002C-EN-P - November 2004
6 Bulletin 1405 (M620) Operating Instructions
displayed is instantaneous phase currents, while the additional
parameters are time-averaged phase currents and peak phase currents.
For power measurements, the main parameters displayed are real
power for each phase. The additional parameters in this group are
apparent power of each phase, total real and apparent power, and
3-phase power factor. When the instrument is displaying the main
parameter of a group, the additional parameters within that group can
be scrolled using the “F” key.
Measurement Modes
The functions of the instrument are accessed as follows:
Table 2
Key Function
Indication Key Press
Duration
“+” Skip to the next measured parameter Short
Auto-sequencing display mode: enable /
disable - “r” Long
Re-set average and peak values - “c” Very long
“F” Sequentially display one parameter type: e.g.,
current Short
Enter set-up mode Very long
“-“ Go back to the previous displayed parameter
The instrument measures voltage and current for each of three phases
in an alternating sequence of 2 seconds each. This corresponds to the
integrating time of the A/D converter circuits. At the same time, the
values of power, power factor (Cos f), and energy consumption are
computed. The energy value is computed for each phase over the
integration period, and the accumulated values are stored in memory.
The measured voltage values are continuously evaluated for over- and
under-voltage occurrences, and the energy transfer rate is converted
to an output pulse rate. Voltage limit alarms and energy unit pulses
are transmitted by relay contacts.
In the auto-sequencing displayed mode, the displayed parameter
change every 6 seconds. The user can halt the auto-sequencing of
displayed parameters, so that one desired parameter is displayed
continuously. Independent of the sequencing mode, the measured
values are updated and displayed in 2-second intervals.