Endress+Hauser iTEMP TMT162, Краткое руководство по эксплуатации

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Wiring TMT162 HART
24 Hauser
ESD – Electrostatic discharge
Protect the terminals against electrostatic discharge. Failure to comply with this instruction can
result in the destruction of parts of the electronics.
3.2 Connecting the sensor
!
Note!
The following connection options are possible for two sensor inputs:
"
Caution!
When connecting 2 sensors ensure that there is no galvanic connection between the sensors
(e.g. caused by sensor elements that are not isolated from the thermowell). The resulting
equalizing currents distort the measurements considerably. In this situation, the sensors have to
be galvanically isolated from one another by connecting each sensor separately to a field
transmitter. The device provides sufficient galvanic isolation (> 2 kV AC) between the input and
output.
3.3 Connecting the device
Fieldbus cable specifications to IEC 61158-2 (MBP), for details, see Operating Instructions (on
CD-ROM).
"
Caution!
• 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.
3.3.1 HART
®
connection
!
Note!
If the HART
®
communication resistance is not built into the power supply, a 250
Ω
communication resistor must be fitted into the 2-wire supply lines.
For connection hints, please take special notice of the documentation supplied by the HART
®
Communication Foundation, specifically HCF LIT 20: “HART, a technical overview”.
Sensor 1:
RTD 2-wire
Sensor 1:
RTD 3-wire
Sensor 1:
RTD 4-wire
Sensor 1:
TC connection
Sensor 2:
RTD 2-wire
YES YES NO YES
Sensor 2:
RTD 3-wire
YES YES NO YES
Sensor 2:
RTD 4-wire
NO NO NO NO
Sensor 2:
TC connection
YES YES YES YES