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5 Connecting to power supply
VEGACAL 62 • Profibus PA
30025-EN-160331
In the connection box or T-distributor, the screen of the short stub to
the sensor must not be connected to ground potential or to another
cable screen. The cable screens to the power supply unit and to the
next distributor must be connected to each other and also connected
to ground potential via a ceramic capacitor (e.g. 1 nF, 1500 V). The
low frequency potential equalisation currents are thus suppressed,
but the protective effect against high frequency interference signals
remains.
The total capacitance of the cable and of all capacitors must not
exceed 10 nF in Ex applications.
Take note of the corresponding installation regulations for Ex applica-
tions. In particular, make sure that no potential equalisation currents
flow over the cable screen. In case of grounding on both sides this
can be achieved by the use of a capacitor or a separate potential
equalisation.
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
