VEGA VEGALOG 571 EP (Ex) - Manual (Page 14)

5 Connecting to power supply
5.1 Preparing the connection
Always keep in mind the following safety instructions:
l
Connect only in the complete absence of line voltage
l
If overvoltage surges are expected, overvoltage arresters
should be installed
In hazardous areas you should take note of the appropriate
regulations, conformity and type approval certificates of the
sensors and power supply units.
The module card is powered by the common power supply unit
of the VEGALOG system.
You can find detailed specifications on voltage supply in
chapter "Technical data" in the "Supplement".
5.2 Connection cable and bus configuration
For the connection technology, take note of "Profibus directive
of the Profibus user organisation e.V." (order no. 2.141) as well
as the Profibus specification.
The connection cables must be specified for the expected
operating temperatures and must have an outer diameter of
6 … 12 mm to ensure the seal effect of the cable gland on the
sensor.
Only screened cable can offer reliable protection against
electromagnetic interference. Screened and twisted cables are
hence prescribed according to the Profibus specification
(IEC 61158-2).
The EP(Ex) card generates together with the cable a bus
segment, the beginning and end of which must be terminated
by a bus termination. This termination is made via two
terminating resistors. In Ex area, they must have an
appropriate approval.
Note:
A terminating resistor is already permanently intregrated in the
EP(Ex) cards. Hence only one termination of the bus end is
necessary.
Note safety instructions
Take note of safety
instructions for Ex
applications
Select power supply
Connection resistance on
Profibus PA
14 VEGALOG 571 EP (Ex) - Input card Profibus PA
Connecting to power supply
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