Endress+Hauser iTEMP TMT85, Руководство по эксплуатации

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Electrical connection iTEMP TMT85
20 Hauser
• Using a conventional cable gland →  20
• Using the fieldbus connector (optional, available as an accessory) →  20
Risk of damage
• Switch off the power supply before installing or connecting the head transmitter.
Failure to observe this may result in destruction of parts of the electronics.
• Grounding via one of the grounding screws (terminal head, field housing) is
recommended.
• 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 must be grounded on one side only, i.e. it must not be
connected to the ground terminal of the housing (terminal head, field housing). The
shield that is not connected should be insulated!
• We recommend that the fieldbus not be looped using conventional cable glands. If
you replace just one measuring device later on, bus communication will have to be
interrupted.
Cable gland or entry
Please also observe the general procedure on →  16.
2 1
3
4
5
6
A0041953
 8 Connecting the signal cables and power supply
1 Head transmitter installed in field housing
2 Head transmitter installed in terminal head
3 Terminals for fieldbus communication and power supply
4 Internal ground connection
5 External ground connection
6 Shielded fieldbus cable
• The terminals for connecting the fieldbus (1+ and 2-) are not polarity sensitive.
• Conductor cross-section:
• Max. 2.5 mm 2 for screw terminals
• Max. 1.5 mm 2 for spring terminals. Min. stripping length of cable
10 mm (0.39 in).
• A shielded cable must be used for the connection.
Fieldbus connector
As an option, a fieldbus connector can be screwed into the terminal head or field housing
instead of a cable gland. Fieldbus connectors can be ordered as accessories from Endress
+Hauser (see →  47).
The connection technology of FOUNDATION Fieldbus
TM allows measuring devices to be
connected to the fieldbus via uniform mechanical connections such as T-boxes, junction
boxes, etc.