Siemens SIPROTEC 7VU681 User Manual page 62

Mounting And Commissioning
3.1 Mounting And Connections
uniformly for a rated current, i.e. one jumper each (X61 through X63) for each of the input transformers and
additionally the common jumper X60.
If nominal current ratings are to be changed exceptionally, then the new change must be notified to the device
at addresses 252 CT Rated Secondary Current Line1; 254 CT Rated Secondary Current Line2;256 CT
Rated Secondary Current Busbar ;258A Earth CT Rated Secondary Current Busbar in the Power System
Data.
Note
The jumper settings must correspond to the secondary device currents configured . Otherwise the device is
blocked and outputs an alarm.
The rated secondary current Line1 and Line2 must set same, because there is a common jumper X60.
Pickup Voltage for Binary Inputs
When the device is delivered the binary inputs are set to operate with a voltage that corresponds to the rated
voltage of the power supply. If the rated values differ from the power system control voltage, it may be
necessary to change the switching threshold of the binary inputs.
To change the switching threshold of a binary input, one jumper must be changed for each input. The allocation
of the plug-in jumpers to the binary inputs and their actual positioning are described in this Section.
Contact Mode for Binary Outputs
Input/output modules can have relays that are equipped with changeover contacts. For this it is necessary to
rearrange a jumper. For which relay on which board this applies is described in this Section under "Input/Output
Board C-I/O -1" , "Input/Output Board C-I/O -10" and "Input/Output Board C-I/O -11".
Replacing Interface
The serial interfaces can only be exchanged in the versions for panel flush mounting and cubicle mounting.
Which interfaces can be exchanged, and how this is done, is described in this Section under the margin title
"Replacing Interface Modules".
Terminating Resistors for RS485 and Profibus DP (Electrical)
For reliable data transmission the RS485 bus or the electrical Profibus DP must be terminated with resistors at
the respective last device on the bus. For this purpose termination resistors are provided on the PCB of the C-
CPU-2 processor board and on the RS485 or PROFIBUS interface module which can be connected via
jumpers. Only one of the three options may be used. The physical location of the jumpers on the PCB is
described in this Section under the margin title "Processor Board C-CPU-2", and under the margin title "Bus-
Capable Serial Interfaces" for the interface modules. Both jumpers must always be plugged in the same way.
The terminating resistors are disabled on unit delivery.
Spare Parts
Spare parts may be the backup battery that maintains the data in the battery-buffered RAM when the voltage
supply fails, and the miniature fuse of the internal power supply. Their physical location is shown in Figure 3-
3. The ratings of the fuse are printed on the board next to the fuse itself. When replacing the fuse, please
observe the guidelines given in the SIPROTEC 4 System Manual /1/ in the chapter "Maintenance" and
"Corrective Action / Repairs".
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SIPROTEC, 7VU681, User Manual
C53000-G1176-C368-1, Release Date 07.2012