Rockwell Automation 1404-M4_M5_M6_M8 Powermonitor 3000 Installation Instructions, PRIOR to Firmware rev. 3.0 - Manual (Page 19)

Publication 1404-IN007D-EN-P - October 2004
Powermonitor 3000 19
Bandwidth Error
For fundamental 50 Hz or 60 Hz measurements, bandwidth error has
no affect on accuracy. However, for waveforms with significant
harmonic content, the user-supplied PTs and CTs may attenuate
higher harmonics. Most instrument quality PTs have a flat frequency
response out to 3 kHz, or the 50th harmonic on a 60 Hz system.
Current transformers, especially older, existing units, tend to be less
linear, with a flat response only out to 300 Hz, or the fifth (60 Hz)
harmonic. Wide-band instrument CTs are available for improved
frequency response. Bandwidth error cannot be corrected by
adjusting the Powermonitor 3000 configuration.
In addition, operation of either the PTs or CTs at extremely low
frequencies may also cause saturation and resulting magnitude and
phase errors.
For more detailed information on instrument transformer accuracy and
power measurement, refer to publication 1403-1.0.2, “Bulletin 1403
Powermonitor II Tutorial”.
Wiring
Wiring of the Powermonitor 3000 includes the following steps:
•
Connection of voltage and current signals from PTs and CTs
•
Connection of control power
•
Connection of status inputs and status/control outputs
•
Communications wiring
Please follow these guidelines to help assure reliable, trouble-free
operation of your Powermonitor 3000.
ATTENTION
Only qualified personnel, following accepted safety
procedures, should install, wire and service the
Powermonitor 3000 and its associated components.
Before beginning any work, disconnect all sources of
power and verify that they are de-energized and
locked out. Failure to follow these instructions may
result in personal injury or death, property damage
or economic loss.