VEGA VEGALOG 571 CPU and carrier - Manual (Page 14)

5 Connecting to power supply
5.1 General connection instructions
Always observe 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 VEGALOG cards must be powered with extra low voltage
(24 V DC) to keep protection class II. Detailled infromation to
voltage supply is available in the "Technical data" in the
"Supplement". When using a VEGASTAB 593, a reliable
separation from the mains circuits is ensured according to DIN
VDE 0106, part 101.
If voltage supply is not taken over by VEGASTAB, the supply
cable must be looped via the supplied NF filter (type: Schaffner
FN660-10/06). The supply cable after the filter must be wired
with a considerable distance to the signal cables to avoid
couplings.
Note:
Sum the power consumptions of the individual cards and
sensor and select a power supply unit with sufficient power
reserve.
Power supply is connected with standard cable acc. to the
national installation standards.
To connect 4 … 20 mA instruments, standard two-wire cable
without screen can be used. If electromagnetic interference is
expected which is above the test values of EN 61326 for
industrial areas, screened cable should be used.
When connecting Profibus PA sensors, screened cable
according to Profibus specification must be used.
Please make sure that your installation is carried out according
to the Profibus specification. In particular, make sure that the
termination of the bus is done with appropriate terminating
resistors.
Note safety instructions
Take note of safety
instructions for Ex
applications
Select power supply
Selecting the connection ca-
ble
14 VEGALOG 571 - CPU and carrier
Connecting to power supply
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