Rockwell Automation 1426 PowerMonitor 5000 Unit - Manual (Page 27)

Rockwell Automation Publication 1426-UM001F-EN-P - November 2013 27
Install the PowerMonitor 5000 Unit Chapter 2
Current Sensing
Route the CT secondary wiring through the openings in the
PowerMonitor 5000 unit as shown.
Use a shorting terminal block (included in the 1400-PM-ACC accessory kit),
test block, or shorting switch (by user) for CT wiring to permit safely servicing
connected equipment such as the PowerMonitor 5000 unit without de-
energizing the power system.
Use 2.5 mm
2
(14 AWG) or 3.3 mm
2
(12 AWG) (maximum) wiring between the
PowerMonitor 5000 unit and the shorting block. Use 2.5 mm
2
(14 AWG) or
larger wire between the shorting block and the CTs, depending on the length of
the circuit. Longer circuits require larger wire so that the wiring burden does not
exceed the CT burden rating and reduce system accuracy. Note that the diameter
of the current sensing wiring openings is 7 mm (0.27 in.).
When wiring a PowerMonitor 5000 unit to existing CTs and metering devices,
current sensing circuits of the PowerMonitor 5000 unit must be wired in series
with the CT secondary and current sensing circuits of the existing metering
devices.
Do not install overcurrent protection or non-shorting disconnecting means in
CT secondary wiring. Connect the current sensing circuit to a low-impedance
earth ground at only one point.
IMPORTANT Ring lugs are recommended for making CT secondary connections. Standard
ring lugs do not pass through the current sensing openings of the
PowerMonitor 5000 unit. We recommend that the installer pass the wire from
the shorting terminal block through the current sensing opening before
crimping on ring lugs.
To shorting terminal block
and current transformer (CT).
X1
X2
I1
I2
I3
I4