Rockwell Automation 1404-M4_M5_M6_M8 Powermonitor 3000 User Manual, Firmware rev. 3.0 or LATER - Manual (Page 27)

27 Publication 1404-UM001F-EN-P - November 2009 27
Chapter
3
Powermonitor 3000 Unit Operations
The Powermonitor 3000 unit is a microprocessor-based electrical
power- and energy-measuring device. It connects to your three-phase
or single-phase ac power system directly or through instrument
transformers (PTs and CTs). It converts instantaneous voltage and
current values to digital values, and uses the resulting digital values in
calculations of things such as voltage, current, power, and energy. You
may access the resulting metering values manually by using the
display module or automatically by using communication with an
external device or application.
The basic operations of the Powermonitor 3000 unit include the
following:
•
Metering functionality
•
Operational and status indication
•
Operation of the display module
•
Display module menus and parameter structure
•
Setup and configuration by using the display module
•
Data monitoring by using the display module
•
Issuing commands by using the display module
Other power monitor features such as communication, setpoint
operations, I/O operations, data logging, oscillography, harmonics,
sag/swell detection, load factor calculation, and transient detection are
covered later in this manual.
Metering Functionality The power monitor performs calculations on scaled, digital voltage
and current values. Signals connected to the voltage and current
inputs are sampled and their instantaneous values are converted to
digital values in an analog-to-digital (A/D) converter section. These
values are scaled according to configured PT Primary, PT Secondary,
CT Primary, and CT Secondary parameters, and evaluated according
to the configured Wiring Mode parameter. Metering results are
available for display on the display module, in the communication
data tables, and for use in setpoint programming and data logging.
The table on page 28 provides a summary of measurements produced
in each Powermonitor 3000 unit, and notes which measurements you
may view by using the display module.