Endress+Hauser iTEMP TMT142B - Connecting the sensor; Connecting the measuring device

Electrical connection iTEMP TMT142B
16 Endress+Hauser
5.2 Connecting the sensor
NOTICE
‣
ESD - Electrostatic discharge. Protect the terminals from electrostatic discharge.
Failure to observe this may result in the destruction or malfunction of parts of the
electronics.
+
-
1
2
3
4
+
-
3
4
S1
-
+
!
C
B
RD
RD
WH
WH
A
A0052568
 4 Terminal assignment of the field transmitter
A Sensor input, thermocouple (TC) and mV
B Sensor input, RTD and Ω, 4-, 3- and 2-wire
C Bus terminator and power supply
In the event of a thermocouple (TC) measurement, an RTD Pt100 2-wire sensor can
be connected to measure the reference junction temperature. This is connected to
terminals 1 and 3. The reference junction used is selected in the menu: Application →
Sensor → Reference junction
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