Vega VEGABAR 14 Operating Instructions Manual - page 13
13
5 Connecting to power supply
VEGABAR 14 • 4 … 20 mA
22441-EN-161104
5 Connecting to power supply
5.1 Preparing the connection
Always keep in mind the following safety instructions:
Warning:
Connect only in the complete absence of line voltage.
•
The electrical connection must only be carried out by trained
personnel authorised by the plant operator.
•
If overvoltage surges are expected, overvoltage arresters should
be installed.
Power supply and current signal are carried on the same two-wire
cable.Theoperatingvoltagecandifferdependingontheinstrument
version.
Thedataforpowersupplyarespecifiedinchapter"Technical data".
Provide a reliable separation between the supply circuit and the
mains circuits according to DIN EN 61140 VDE 0140-1.
Keepinmindthefollowingadditionalfactorsthatinfluencetheoperat-
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)
•
Influenceofadditionalinstrumentsinthecircuit(seeloadvaluesin
chapter "Technical data")
The instrument is connected with standard two-wire cable without
screen. If electromagnetic interference is expected which is above the
test values of EN 61326 for industrial areas, screened cable should
be used.
Use cable with round cross section. A suitable outer cable diameter
of (see chapter "Technical data")ensuresthesealeffectofthecable
gland.
If screened cable is required, connect the cable screen on both ends
to ground potential.
In electroplating plants as well as plants for cathodic corrosion protec-
tionitmustbetakenintoaccountthatsignificantpotentialdifferences
exist. This can lead to unacceptably high currents in the cable screen
if it is grounded at both ends.
Information:
Themetallicpartsoftheinstrument(processfitting,housing,etc.)are
conductively connected to the ground terminal.
5.2 Connection procedure
Proceed as follows:
1. Loosen the screw on the rear of the plug connector
2. Remove the plug connector and seal from VEGABAR 14
Safety instructions
Voltage supply
Select connection cable
Cable screening and
grounding
Connection via angle
plug connector