Vega VEGAPULS SR 68 Operating Instructions Manual

Also see for VEGAPULS SR 68: Quick setup guide Product information Operating instructions Operating instructions Operating instructions

If screened cable is necessary, connect the cable screen on both endsto ground potential. In the sensor, the screen must be connecteddirectly to the internal ground terminal. The ground terminal on theoutside of the housing must be connected to the potential equalisation(low impedance).If potential equalisation currents are expected, the connection on theprocessing side must be made via a ceramic capacitor (e. g. 1 nF,1500 V). The low frequency potential equalisation currents are thussuppressed, but the protective effect against high frequency interfer-ence signals remains.Warning:Within galvanic plants as well as vessels with cathodic corrosionprotection there are considerable potential differences. Considerableequalisation currents can be caused via the cable screen when thescreen is earthed on both ends.To avoid this, the cable screen must only be connected to groundpotential on one side of the switching cabinet in such applications. Thecable screen must not be connected to the internal ground terminal inthe sensor and the outer ground terminal on the housing not to thepotential equalisation!Information:The metal parts of the instrument (antenna, transmitter, concentrictube, etc.) are conductive connected with the inner and outer groundterminal on the housing. This connection exists either directly metallicor with instruments with external electronics via the screen of thespecial connection cable.You can find specifications to the potential connections within theinstrument in chapter "Technical data".5.2 ConnectionThe connection of the voltage supply and the signal output is carriedout via the spring-loaded terminals in the housing.The connection to the indicating and adjustment module or to theinterface adapter is carried out via contact pins in the housing.Proceed 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) of insulation from the ends of the individual wiresCable screening andgroundingConnection technologyConnection procedureVEGAPULS SR 68 • 4 … 20 mA/HART two-wire 255 Connecting to power supply38294-EN-110209