Connecting - Siemens SITRANS LG250 Operating Instructions Manual

Cable screening and
grounding
Connection technology
Connection procedure
PBD-51041053
On plastic housings, the NPT cable gland or the Conduit steel tube
must be screwed into the threaded insert without grease.
Max. torque for all housings, see chapter "Technical data".
Make sure that the cable screen and grounding are carried out ac-
cording to Fieldbus specification. We recommend to connect the
cable screening to ground potential on both ends.
In systems with potential equalisation, connect the cable screening
directly to ground potential at the power supply unit, in the connection
box and at the sensor. The screen in the sensor must be connected
directly to the internal ground terminal. The ground terminal outside
on the housing must be connected to the potential equalisation (low
impedance).
5.2

Connecting

The voltage supply and signal output are connected via the spring-
loaded terminals in the housing.
Connection to the display and adjustment module or to the interface
adapter is carried out via contact pins in the housing.
Information:
The terminal block is pluggable and can be removed from the
electronics. To do this, lift the terminal block with a small screwdriver
and pull it out. When reinserting the terminal block, you should hear it
snap in.
Proceed as follows:
1. Unscrew the housing lid
2. If a display and adjustment module is installed, remove it by turn-
ing it slightly 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
Fig. 13: Connection steps 5 and 6
1 Single chamber housing
2 Double chamber housing
6. Insert the wire ends into the terminals according to the wiring plan
SITRANS LG250 - Operating Instructions
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