20
5 Connecting to power supply
OPTISOUND 3020 C • Two-wire 4 … 20 mA/HART
30507-EN-190318
If screened cable is required, we recommend connecting the cable
screen on both ends to ground potential. The screening in the sen-
sor must be connected directly to the internal ground terminal. The
ground terminal on the outside of the housing must be connected to
the ground potential (low impedance).
In Ex systems, the grounding is carried out according to the installa-
tion regulations.
5.2 Connection procedure
Proceed as follows:
1. Unscrew the housing lid
2. If a display and adjustment module is installed, remove it by turn-
ing it to the left
3. Loosen compression nut of the cable gland and remove blind
plug
4. Remove approx. 10 cm (4 in) of the cable mantle, strip approx.
1 cm (0.4 in) of insulation from the ends of the individual wires
5. Insert the cable into the sensor through the cable entry
6. Lift the opening levers of the terminals with a screwdriver (see
following illustration)
7. Insert the wire ends into the open terminals according to the wir-
ing plan
Fig. 17: Connection steps 6 and 7
8. Press down the opening levers of the terminals, you will hear the
terminal spring closing
9. Check the hold of the wires in the terminals by lightly pulling on
them
10. Connect the screen to the internal ground terminal, connect the
external ground terminal to potential equalisation
Cable screening and
grounding
