Vega VEGAPULS SR 68 Operating Instructions Manual

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

5 Connecting to power supply5.1 Preparing the connectionAlways keep in mind the following safety instructions:l Connect only in the complete absence of line voltagel If overvoltages are expected, install overvoltage arrestersPower supply and current signal are carried on the same two-wirecable. The voltage supply range can differ depending on theinstrument version.The data for power supply are specified in chapter "Technical data".Provide a reliable separation between the supply circuit and the mainscircuits according to DIN VDE 0106 part 101.Keep the following additional influences for the operating voltage inmind:l Output voltage of the power supply unit can be lower undernominal load (with a sensor current of 20.5 mA or 22 mA in case offault message)l Influence of additional instruments in the circuit (see load values inchapter "Technical data")The signal conditioning instruments VEGAMET and VEGASCAN havedigital sensor recognition. When connecting VEGAPULS SR 68, anup-to-date software version of the signal conditioning instrument isrequired for the signal conditioning instrument. For a software updatego to "Software" under "www.vega.com/downloads".The instrument is connected with standard two-wire cable withoutscreen. If electromagnetic interference is expected which is above thetest values of EN 61326 for industrial areas, screened cable should beused.For instruments with housing and cable gland, use cable with roundcross-section. A cable outer diameter of 5 … 9 mm (0.2 … 0.35 in)ensures the seal effect of the cable gland. If you are using cable with adifferent diameter or cross-section, exchange the seal or use asuitable cable gland.We generally recommend the use of screened cable for HARTmultidrop mode.With plastic housing, the NPT cable gland or the Conduit steel tubemust be screwed without grease into the threaded insert.Max. torque for all housings see chapter "Technical data"Safety instructionsVoltage supplyConnection to signalconditioning instru-mentsConnection cableCable gland ½ NPT24 VEGAPULS SR 68 • 4 … 20 mA/HART two-wire5 Connecting to power supply38294-EN-110209