VEGA VEGAPULS WL 61 Profibus PA - Manual (Page 23)

23
5 Connecting to power supply
VEGAPULS WL 61 • Profibus PA
38062-EN-121011
5 Connecting to power supply
5.1 Preparing the connection
Always keep in mind the following safety instructions:
•
Connect only in the complete absence of line voltage
•
If overvoltage surges are expected, overvoltage arresters should
be installed
Power supply and current signal are carried on the same two-wire
cable. The voltage supply range can differ depending on the instru-
ment version.
The data for power supply are specified in chapter "Technical data".
Provide a reliable separation between the supply circuit and the
mains circuits according to DIN VDE 0106 part 101.
Keep in mind the following additional factors that influence the operat-
ing voltage:
•
Output voltage of the power supply unit can be lower under nomi-
nal load (with a sensor current of 20.5 mA or 22 mA in case of fault
message)
•
Influence of additional instruments in the circuit (see load values in
chapter "Technical data")
Connection is made with screened cable according to the Profibus
specification. Power supply and digital bus signal are carried over the
same two-wire connection cable.
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.
You can find detailed information of the cable specification, installa-
tion and topology in the "Profibus PA - User and Installation Guide-
line" on www.profibus.com.
5.2 Wiring plan
1
2
Fig. 23: Wire assignment fix-connected connection cable
1 brown (+) and blue (-) to power supply or to the processing system
2 Shielding
Safety instructions
Voltage supply
Connection cable
Wire assignment, con-
nection cable