Vega VEGABAR 82 Operating Instructions Manual

Also see for VEGABAR 82: Product information Operating instructions Quick setup guide Operating instructions Operating instructions

Contents

225 Connecting to power supplyVEGABAR 82 • 4 … 20 mA45027-EN-1903205 Connecting to power supply5.1 Preparing the connectionAlways keep in mind the following safety instructions:• Carry out electrical connection by trained, qualified personnelauthorised by the plant operator• If overvoltage surges are expected, overvoltage arresters shouldbe installedWarning:Connect only in the complete absence of line voltage.Power supply and current signal are carried on the same two-wirecable. The operating voltage can differ depending on the instrumentversion.The data for power supply are specified in chapter "Technical data".Provide a reliable separation between the supply circuit and themains circuits according to DIN EN 61140 VDE 0140-1.Power the instrument via an energy-limited circuit acc. to IEC 61010-1, e.g. via Class 2 power supply unit.Keep in mind the following additional factors that influence the operat-ing voltage:• Lower output voltage of the power supply unit under nominal load(e.g. with a sensor current of 20.5 mA or 22 mA in case of fault)• Influence of additional instruments in the circuit (see load values inchapter "Technical data")The instrument is connected with standard two-wire cable withoutscreen. If electromagnetic interference is expected which is above thetest values of EN 61326-1 for industrial areas, screened cable shouldbe used.Use cable with round cross section for instruments with housing andcable gland. Use a cable gland suitable for the cable diameter toensure the seal effect of the cable gland (IP protection rating).If screened cable is required, we recommend connecting the cablescreening on both ends to ground potential. In the sensor, the cablescreening must be connected directly to the internal ground terminal.The ground terminal on the outside of the housing must be connectedto the ground potential (low impedance).In Ex systems, the grounding is carried out according to the installa-tion regulations.In electroplating plants as well as plants for cathodic corrosion protec-tion it must be taken into account that significant potential differencesexist. This can lead to unacceptably high currents in the cable screenif it is grounded at both ends.Safety instructionsVoltage supplyConnection cableCable screening andgrounding