Vega VEGACAL 62 Operating Instructions Manual

Also see for VEGACAL 62: Safety manual User manual Operating instructions Operating instructions

In systems with potential equalisation, connect the cable screendirectly to ground potential at the power supply unit, in the connectionbox and at the sensor. The screen in the sensor must be connecteddirectly to the internal ground terminal. The ground terminal outside onthe housing must be connected to the potential equalisation (lowimpedance).In systems without potential equalisation, connect the cable screendirectly 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 tothe sensor must not be connected to ground potential or to anothercable screen. The cable screens to the power supply unit and to thenext distributor must be connected to each other and also connectedto ground potential via a ceramic capacitor (e.g. 1 nF, 1500 V). The lowfrequency potential equalisation currents are thus suppressed, but theprotective effect against high frequency interference signals remains.The total capacitance of the cable and of all capacitors must not exceed10 nF in Ex applications.Take note of the corresponding installation regulations for Exapplications. In particular, make sure that no potential equalisationcurrents flow over the cable screen. In case of grounding on both sidesthis can be achieved by the use of a capacitor or a separate potentialequalisation.5.2 Connection procedureProceed as follows:1 Unscrew the housing cover2 If an indicating and adjustment module is installed, remove it byturning it slightly to the left.3 Loosen compression nut of the cable entry4 Remove approx. 10 cm (4 in) of the cable mantle, strip approx.1 cm (0.4 in) insulation from the ends of the individual wires5 Insert the cable through the cable gland into the sensor6 Lift the opening levers of the terminals with a screwdriver (seefollowing illustration)Cable screening andgrounding16 VEGACAL 62 • Profibus PA5 Connect to power supply30025-EN-090603