VEGA WEIGHTRAC 31 Profibus PA - Manual (Page 24)

24
5 Connecting to power supply
WEIGHTRAC 31 • Profibus PA
43837-EN-131119
directly to the internal ground terminal. The ground terminal outside
on the housing must be connected to the potential equalisation (low
impedance).
In systems without potential equalisation with cable screening on
both sides, 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). Low-frequency potential equali-
sation currents are thus suppressed, but the protective effect against
high frequency interference signals remains.
The voltage supply and signal output are connected via the spring-
loaded terminals in the housing.
The connection to the display and adjustment module or to the inter-
face adapter is carried out via contact pins in the housing.
Proceed as follows:
The procedure applies to instruments without explosion protection.
1. Unscrew the big housing cover
2. Loosen compression nut of the cable entry gland
3. 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
4. Insert the cable into the sensor through the cable entry
Connection technology
Connection procedure