VEGA VEGASON 65 Profibus PA - Manual (Page 23)

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 according to Profibus specifications
Tip:
We recommend VEGA overvoltage arrester B63-32.
In hazardous areas you should take note of the appropriate
regulations, conformity and type approval certificates of the sensors
and power supply units.
Supply voltage and current output are carried on separate two-wire
connection cables if reliable separation is required. The supply voltage
range can differ depending on the instrument version.
The data for power supply are specified in chapter "Technical data".
This instrument is designed in protection class I. To maintain this
protection class, it is absolutely necessary that the ground conductor
be connected to the internal ground terminal. Take note of the general
installation regulations.
As a rule, connect the instrument to vessel ground (potential
euqalisation) or in case of plastic vessels to the next ground potential.
For this purpose there is a ground terminal on the side of the
instrument housing.
For power supply, an approved installation cable with PE conductor is
necessary.
Connection is carried out with screened cable according to Fieldbus
specification.
Use cable with round cross-section. A cable outer diameter of 5 … 9 mm
(0.2 … 0.35 in) ensures the seal effect of the cable gland. If you are
using cable with a different diameter or cross-section, exchange the
seal or use a suitable cable gland.
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 instruc-
tions for Ex ap-
plications
Select power supply
Selecting connection
cable
VEGASON 65 • Profibus PA 23
5 Connecting to power supply
28788
-
EN
-081127