Electro Industries/GaugeTech
Doc # E107706 V1.254-1
Chapter 4Electrical Installation
4.1:
Wiring
the
Monitored
Inputs
and
Voltages
QSelect a wiring diagram from Section 4.8 that best suits your application. Wire the Nexus 1250/1252
exactly as shown. For proper operation, the voltage connection must be maintained and must
correspond to the correct terminal. Program the CT and PTRatios in the Device Profile section of
the Communicator EXT software; see the Communicator EXTUser Manual for details.
The cable required to terminate the voltage sense circuit should have an insulation rating greater than
600V AC and a current rating greater than 0.1 Amp.
Use a minimum of 14 AWG wire for all phase voltage and current connections.
4.2:
Fusing
the
Voltage
Connections
QFor accuracy of the readings and for protection, EIG requires using 0.25-Amp rated fuses on all
voltage inputs as shown in the wiring diagrams (see section 4.8).
The Nexus Meter can handle a maximum voltage of 150V phase to neutral and 300Vphase to phase.
Potential Transformers (PTs) are required for higher voltages with the standard rating. With Option -
G, the direct voltage input is extended to 300Vphase to neutral and 600V phase to phase.
4.3:
Wiring
the
Monitored
Inputs
-
VRef
QThe Voltage Reference connection references the monitor to ground or neutral.
4.4:
Wiring
the
Monitored
Inputs
-
VAux
QThe Voltage Auxiliary connection is an auxiliary voltage input that can be used for any desired
purpose, such as monitoring neutral to ground voltage or monitoring two different lines on a switch.
4.5:
Wiring
the
Monitored
Inputs
-
Currents
QInstall the cables for the current at 600V AC minimum insulation. The cable connector should be
rated at 10 Amps or greater and have a cross-sectional area of 14 AWG.
QMount the current transformers (CTs) as close as possible to the meter. The following table
illustrates the maximum recommended distances for various CT sizes, assuming the connection is via
14 AWG cable.