VEGA Capacitive electrodes EK Profibus PA - Manual (Page 20)

20 Capacitive electrodes EK - Profibus PA
Electrical connection
3 Electrical connection
3.1 Connection instructions
Note
Switch off the power supply before starting
connection work.
Connect the supply voltage acc. to the
following connection diagrams.
Note
If strong electromagnetic interference is
expected, we recommend using screened
cable. The screening of the cable should only
be earthed at one end (sensor end).
Always connect the instrument to vessel
ground (PA): For this purpose, there is a
terminal on the side of the housing. This
connection is also used to supply the ground
reference potential as well as to drain off
electrostatic charges.
The electronics module CAP E34 PA requires
a supply voltage of 12...36 V DC. The supply
voltage and the digital output signal are led
via the same two-wire connection cable to the
terminals. The external energy is provided by
a segment coupler.
Note the following instructions for electrical
connection:
- Connection must be made according to
the country-specific installation standards
(e.g. in Germany acc. to the VDE
regulations).
- The electrical connection must have a
protective measure against polarity
reversal.
- The connection of field instruments is
generally made via T-adapters on stubs.
- Screened cable is recommended for
connection (cable types, see chapter "1.3
Technical data"). The shielding must be
connected on both ends (on the T-adapter
and on the instrument).
- For use in Ex areas, the installation
regulations must be noted.
3.2 Wiring plan
Note
The oscillator is independent of the electrode
and can be exchanged on site.
1 2 5 6 7 8
PROFIBUS + -
EEx ia IIC
see certificate
on 8 7 6 5 4 3 2 1
R
Segmentkoppler