KROHNE IFC 300 Converter Quickstart EN - Manual (Page 51)

ELECTRICAL CONNECTIONS
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IFC 300
www.krohne.com 08/2010 - 4000070303 - QS IFC 300 R06 en
Flow sensors with protection class IP 68 can not be opened anymore. The cables are factory
connected and labeled as follows.
3.7 Grounding the measuring sensor
3.7.1 Classical method
• The measuring sensor must be properly grounded.
• The grounding cable should not transmit any interference voltages.
• Do not use the grounding cable to connect more than one device to ground at the same time.
• In hazardous areas, grounding is used at the same time for equipotential bonding. Additional
grounding instructions are provided in the separate Ex documentation, which are only
supplied together with hazardous-duty equipment.
• The measuring sensors are connected to ground by means of a functional grounding
conductor FE.
• Special grounding instructions for the various measuring sensors are provided in the
separate documentation for the measuring sensor.
• The documentation for the measuring sensor also contain descriptions on how to use
grounding rings and how to install the measuring sensor in metal or plastic pipes or in pipes
which are coated on the inside.
Figure 3-37: Labeled cables for IP 68 versions
1 Mains power (10 = blank, 11 = blue, 12 = black)
2 Field current (7 = white, 8 = green)
3 Data interface (black wires, C = marked "1", D = marked "2", E = marked "3")
4 Electrodes (1 = blank, 2 = white, 3 = red)
CAUTION!
There should be no difference in potential between the measuring sensor and the housing or
protective earth of the signal converter!