VEGA VEGASON 64 Foundation Fieldbus - Manual (Page 24)

In systems without potential equalisation, connect the cable screen
directly to ground potential at the power supply unit and at the sensor.
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.
Take note of the corresponding installation regulations for Ex
applications. 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
Warning:
Before connecting to voltage supply, the plug connection between
transducer and remote electronics must be provided in idle condition
(see illustration below). Non-observance will damage the electronics!
1
2 3
Fig. 18: Plug connector between transducer and socket of electronics housing
1
Socket electronics housing
2 Plug connector
3 Connection piece, transducer tube
Only then, the sensor may be connected to voltage supply.
Proceed as follows:
1 Unscrew the housing cover
2 Loosen compression nut of the cable entry
Select connec-
tion cable for Ex
applications
24 VEGASON 64 • Foundation Fieldbus
5 Connecting to power supply
28793
-EN
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