Connecting The Measuring Device; Cable Glands Or Entries; Connecting The Hart Communication Resistor - Endress+Hauser iTEMP TMT162 Operating Instructions Manual

iTEMP TMT162
Endress+Hauser
5.3

Connecting the measuring device

5.3.1

Cable glands or entries

CAUTION
L
Risk of damage
‣
Switch off power supply before installing or connecting the device. Failure to observe
this may result in destruction of parts of the electronics.
‣
If the device has not been grounded as a result of the housing being installed, we
recommended grounding it via one of the ground screws. Observe the grounding
concept of the plant! Keep the cable shield between the stripped fieldbus cable and the
ground terminal as short as possible! Connection of the functional grounding may be
needed for functional purposes. Compliance with the electrical codes of individual
countries is mandatory.
‣
If the shielding of the fieldbus cable is grounded at more than one point in systems that
do not have additional potential equalization, mains frequency equalizing currents can
occur that damage the cable or the shielding. In such cases the shielding of the fieldbus
cable is to be grounded on one side only, i.e. it must not be connected to the ground
terminal of the housing. The shield that is not connected should be insulated!
• The terminals for the fieldbus connection have integrated polarity protection.
• Cable cross-section: max. 2.5 mm²
• A shielded cable must be used for the connection.
Follow the general procedure. →  15.
 6 Connecting the device to the fieldbus cable
1 Fieldbus terminals - fieldbus communication and power supply
2 Shielded fieldbus cable
3 Ground terminals, internal
4 Ground terminal (external, relevant for remote version)
5.3.2 Connecting the HART® communication resistor
If the HART® communication resistor is not integrated into the power supply unit, it is
necessary to incorporate a communication resistor of 250 Ω into the 2-wire cable. For
the connection, also refer to the documentation published by the HART® FieldComm
Group, particularly HCF LIT 20: "HART, a technical summary".
3
4 2
1
5
4 3
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+
3
+
6
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Wiring
1
2
3
4
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