Endress+Hauser HART iTEMP TMT142B, Руководство по эксплуатации

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iTEMP TMT142B Electrical connection
Hauser 13
5.3 Connecting the measuring device
5.3.1 Cable glands or entries
L
CAUTION
Risk of damage
‣
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!
Cable specification
• A normal device cable suffices if only the analog signal is used.
• A shielded cable is recommended for HART® communication. Observe grounding
concept of the plant.
• The terminals for the fieldbus connection have integrated polarity protection.
• Cable cross-section: max. 2.5 mm²
Follow the general procedure. →  11
1
2
3
4
+
-
1
2
3
4
+ -
3
4
-
+
!
A0041526
 4 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