Rockwell Automation 1404-M4_M5_M6_M8 Powermonitor 3000 User Manual, Firmware rev. 3.0 or LATER - Manual (Page 49)

Publication 1404-UM001F-EN-P - November 2009 49
Powermonitor 3000 Unit Operations Chapter 3
PT and CT Ratios
You may directly connect the voltage inputs of the power monitor to
power systems rated at 600V line-to-line or less. Above 600V, you
need potential transformers (PTs) to step down the power system
voltage to one that is measurable. Most commercially available PTs
have a secondary rated voltage of 120V (150V full-scale).
Nearly every power monitor installation requires CTs to step down the
power system current to a value of 5 A full-scale.
To perform basic configuration, set the primary and secondary voltage
and current ratings of your PTs (if used) and CTs. If your system
configuration includes a neutral current CT, you need to separately
configure the I4 CT ratio.
•
PT primary: range 1…10,000,000, default 480
•
PT secondary: range 1…600, default 480
•
CT primary: range 1…10,000,000, default 5
•
CT Secondary: range 1…5, default 5
•
I4 primary and I4 secondary: same as CT primary and secondary
For direct connection to power systems of 600V, set the PT ratio to
600:600. For a 480V system, set the PT ratio to 480:480.
Nominal system voltage (M6, M8 only)
The M6 and M8 models use the nominal voltage setting for calculating
the default sag and swell setpoint high and low limits. For Wye and
single-phase wiring modes, set this value to the PT primary-side
nominal line-to-neutral. For all other wiring modes, set this parameter
to the PT primary-side nominal line-to-line voltage.
Range 1…10,000,000, default 480.
Refer to the Powermonitor 3000 Installation Instructions, publication
1404-IN007, for information on selecting and installing PTs and CTs.
TIP
When setting a parameter, you may press and hold the up arrow or
down arrow key for a few seconds to increase the rate the value
increments or decrements.