Connecting The Measuring Unit; Cable Glands Or Entries - Endress+Hauser iTEMP TMT 165 FOUNDATION Fieldbus Betriebsanleitung

FOUNDATION Fieldbus temperature transmitter
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Endress+Hauser
Shielding should be connected as often as possible with the reference ground. The
national regulations and guidelines governing the installation of electrical equipment
also apply where relevant!
Where there are large differences in potential between the individual grounding points,
only one point of the shielding is connected directly with the reference ground. In
systems without potential equalisation, cable shielding of fieldbus systems should only
be grounded on one side, for example at the fieldbus supply unit or at safety barriers.
Caution!
If the cable shielding is grounded at more than one point in systems without potential
equalisation, network frequency equalisation currents can occur that damage the bus
cable or the bus shielding and substantially affect signal transmission.
Bus termination
The start and end of each fieldbus segment are always to be terminated with a bus
terminator. With various junction boxes (not ex-rated) the bus termination can be
activated via a switch. If this is not the case a separate bus terminator must be installed.
Note the following points in addition:
• In the case of a branched bus segment the device furthest from the segment connec-
tor represents the end of the bus.
• If the fieldbus is extended with a repeater then the extension must also be terminated
at both ends.
Further information
General information and further notes on connections can be found on the website
(www.fieldbus.org) of the Fieldbus FOUNDATION.
4.2

Connecting the measuring unit

Field instruments can be connected to the FOUNDATION Fieldbus in two ways:
• Connection via conventional cable gland → chapter 4.2.1
• Connection using prefabricated fieldbus connector (option) → chapter 4.2.2
Caution!
The ATEX, FM, CSA certification for pressure encapsulation (Ex
with units TMT165-xx1xxx and TMT165-xx2xxxx.

4.2.1 Cable glands or entries

What needs to be done:
1. Unscrew the terminal cover from the transmiter housing.
2. Feed the sensor cable and fieldbus cable through the respective cable entries.
Note:
A TMT 165 with a mounted fieldbus connection socket is also available as an option.
Further information can be found on page 91.
4 Wiring
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