Vega VEGAMET 141 - Connecting to Power Supply; Preparing the Connection; Sensor Input Mode Active;Passive; Connecting

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5 Connecting to power supply
VEGAMET 141 • 4 … 20 mA
63728-EN-210129
5 Connecting to power supply
5.1 Preparing the connection
Always keep in mind the following safety instructions:
•
The electrical connection must only be carried out by trained,
qualiedpersonnelauthorisedbytheplantoperator.
•
If overvoltage surges are expected, overvoltage arresters should
be installed.
Warning:
Only connect or disconnect in de-energized state.
Thedataforpowersupplyarespeciedinchapter"Technical data".
The voltage supply is connected with standard cable according to the
national installation standards.
Standard two-wire cable can be used to connect the sensors.
Note:
If the temperatures are too high, the cable insulation can be dam-
aged. Hence keep apart from the ambient temperature also the self-
heating of the instrument for the temperature resistance of the cable
in the connection compartment in mind
1)
.
When used in the USA/Canada, only cables with copper conductors
may be used.
5.2 Sensor input mode active/passive
Through the selection of the terminals, you can choose between ac-
tive and passive operation of the sensor input.
•
In active mode, the controller provides the power for the con-
nected sensors. Power and measurement data are transmitted
over the same two-wire cable. This mode is provided for connec-
tion of measuring transducers without separate power supply
(sensors in two-wire version).
•
In passive mode the sensors are not powered, only the measured
value is transmitted. This input is for connection of transmitters
with their own separate voltage supply (sensors in four-wire ver-
sion). The VEGAMET 141 can also be looped into the existing
circuit like a normal ammeter.
Note:
With a VEGAMET 141 in Ex version, the passive input is not available.
5.3 Connecting
The power supply and the inputs and outputs are connected via
removablescrewterminals.Youcanndinformationonthemax.wire
cross-section in the technical data.
Safety instructions
Voltage supply
Connection cable
Connection technology
1)
 Withanambienttemperature≥50°C(122°F)theconnectioncableshould
besuitableforanambienttemperaturewhichisatleast20°C(36°F)higher.