Wiring; Overview; Sensor Connection; Connecting The Measurement Unit - Endress+Hauser iTEMP TMT184 PROFIBUS-PA Manuel De Mise En Service

4 Wiring

Wiring overview

Sensor connection

Connection measuring unit
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50
4 Wiring
4.1

Overview

Terminal layout

ƒig. 5: Head transmitter wiring
4.2 Sensor connection
Terminal layout
Make connection between sensor cables and head transmitter terminals (terminals 3 to 6) according
to the terminal connection diagram (s. fig. 5).
4.3

Connecting the measurement unit

4.3.1 Terminal layout
Open the PG cable glands on the connection head or field housing. Feed the cable through the PG
cable gland and connect the bus cables to terminals 1 and 2 as shown in s. fig. 5.
When connecting the transmitter in a Ex application please take note of the separate Ex documen-
tation.
Note!
The terminals screws must be completely tightened.
4.3.2

Screen and ground

When designing the screen and ground concept of a fieldbus system, there are three important
aspects to take note of:
• Make sure that the electromagnetic compatibility (EMC) is correct
• Explosion security
• Personnel security
In order to guarantee optimum electromagnetic compatibility, it is important to make sure that the
system components and the cable that joins these are screened continuously. Ideally this cable
screening is connected to the metal housing of the connected field units. Because these are generally
connected to the ground cable it can be assumed that the bus cable screen is well grounded. This
optimum system for electromagnetic compatibility and personnel protection can be used in plants
operating with an optimum potential compensation system. On plants without potential compen-
sation, it is possible that mains frequency compensation currents (50 Hz.) can flow between two
grounding points. In unfavourable cases this could exceed the permitted screen current and damage
the cable.
2
PROFIBUS-PA ®
bus connection
1
2-wire
TC RTD
6
6
3
4
4-wire
3-wire
RTD RTD
6 6
6
5
5
3
3
3
Endress+Hauser
TMT184
6
6
5
5
4
4
3
3