NivoRadar
®
Continuous level measurement
Series NR 4100
Technical information / Instruction manual
page 24
Connecting to power supply
Preparing the connection
Always keep in mind the following safety instructions:
•
Carry out electrical connection by trained, qualified personnel
authorised by the plant operator
Warning:
Only connect or disconnect in de-energized state.
The data for power supply are specified in chapter " Technical
data".
Note:
Power the instrument via an energy-limited circuit (power max.
100 W) acc. to IEC 61010-1, e.g.
•
Class 2 power supply unit (acc. to UL1310)
•
SELV power supply unit (safety extra-low voltage) with suitable
internal or external limitation of the output current
Keep in mind the following additional factors that influence the
operating voltage:
•
Lower output voltage of the power supply unit under nominal
load (e.g. with a sensor current of 20.5 mA or 22 mA in case of
fault signal)
•
Influence of additional instruments in the circuit (see load values
in chapter " Technical data")
The device is supplied with a fixed connected cable. If an extension
is required, a standard two-wire cable can be used.
If electromagnetic interference is expected which is above the test
values of EN 61326-1 for industrial areas, shielded cable should be
used.
Shielded cable generally necessary in HART multidrop mode.
We recommend to connect the cable screening to ground potential
at one end on the supply side when using shielded cable.
Wiring plan
1
2
3
Fig. 21: Wire assignment in permanently connected connection cable
Safety instructions
Voltage supply
Connection cable
Cable screening and
grounding
Wire assignment, con-
nection cable
