Fieldbus Connection - Endress+Hauser iTEMP TMT125 Bedienungsanleitung

Wiring
ESD - Electrostatic discharge
Protect the terminals from electrostatic discharge. Failure to observe this may result in
destruction of parts of the electronics.
The following identifying values must be observed when connecting fieldbus
transmission lines:
• The insulating length of the wire is 9 mm (0.35").
• Wire cross-section 0.2 mm to 2.5 mm or AWG 24 to 14.
• If a cable, consisting of fine wire is in use, the ends of the leads must be protected (e. g. with
core cable ends).
• Tightening torque of the screw terminals (if present) 0.4...0.5 Nm.
• If a Thermocouple is connected to the terminals H and L of the transmitter, it is not allowed
to connect something to the terminals + and -.
• A fieldbus transmission line with an insulation voltage between the bus line and shield of at
least 500 V must be used for intrinsically safe fieldbus segments.
!
Note!
The service interface is for parameterization only. It fulfills the type of protection EEx ia IIC/IIB
resp. EEx ib IIC/IIB with the following values:
U = 7.2 V
O
I = 29.1 mA
O
P = 52.38 mW
O
L = 0
i
C = 0
i
!
Note!
Tasks for parameterization via the service interface must only be performed by Endress+Hauser
service only!
4.2

Fieldbus connection

4.2.1 Cable glands or entries
• If the device has not been grounded as a result of the housing being installed, we recommend
grounding it via one of the ground screws. Observe the grounding concept of the plant!
Between the stripped fieldbus cable and the ground terminal, the cable shielding should be
kept as short as possible.
• Risk of damaging the fieldbus cable!
– If the shielding of the fieldbus cable is grounded at more than one point in systems without
additional potential matching, power supply 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 only one side, i.e. it must not be connected to the ground terminal of the
housing. The shield that is not connected should be insulated!
30
Characteristic curve: linear
Only for connection of intrinsically safe circuits
U = 5 V
i
TMT125
Endress+Hauser