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

20 Capacitive electrodes EL - 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 according to the
following connection diagrams.
Note
If strong electromagnetic interference is ex-
pected, we recommend using screened
cable. The screening of the cable should only
be earthed on one end, i.e. the sensor end
(electrode).
Always connect the instrument to vessel
ground (PA). For this purpose, there is a
terminal on the side of the housing. This con-
nection 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 9 … 32 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 pro-
tective measure against polarity reversal.
- The connection of field instruments is gen-
erally made via T-adapters on stubs.
- Screened cable is recommended for con-
nection (cable types see chapter "1.3 Tech-
nical data"). The shielding must be con-
nected on both ends (on the T-adapter and
on the instrument).
- For use in Ex areas, the installation regula-
tions must be noted.
3.2 Wiring plan
Note
The oscillator is dependent on 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
Segment coupler