Mounting and Commissioning
3.1 Mounting and Connections
SIPROTEC, 7SD5, Manual
C53000-G1176-C169-5, Release date 02.2011
501
The induced voltage can be calculated with the following formula:
U
i
= 2
π
f · M ·
I
k1
· l · r
1
· r
2
with
U
i
= induced longitudinal voltage in V,
f
= nominal frequency in Hz,
M
= mutual inductance between power line and pilot wires in mH/km,
I
k1
= maximum earth fault current via power line in kA,
l
= distance of the power line with parallel pilot wires in km,
r
1
= reduction factor of power cable (r
1
= 1 for overhead lines),
r
2
= reduction factor of pilot wire cable.
The calculated induced voltage should neither exceed 60% of the test voltage of the pilot wires nor of the device
connections (binary inputs and outputs). Since the latter were produced for a test voltage of 2kV, only a
maximum induced longitudinal voltage of 1.2kV is allowed.
3.1.2
Hardware Modifications
3.1.2.1
General
A subsequent adaptation of hardware to the power system conditions can be necessary for example with
regard to the control voltage for binary inputs or termination of bus-capable interfaces. Follow the procedure
described in this section, whenever hardware modifications are carried out.
Auxiliary voltage
There are different power supply voltage ranges for the auxiliary voltage (refer to the Ordering Information in
Appendix A.1). The versions for DC 60 V/110 V/125 V and DC 110 V/125 V/220 V/250 V, AC 115 V are inter-
convertible. Jumper settings determine the rating. The assignment of these jumpers to the nominal voltage
ranges and the spatial layout on the PCB are described further below at „Input/Output Module C-I/O-1“ and
„Input/Output Module C-I/O-10“. On delivery of the device, all jumpers are correctly arranged according to the
specifications on the rating plate and do not need to be changed.
Life contact
The life contact of the device is a changeover contact from which either the NC contact or the NO contact can
be connected to the device terminals via a plug-in jumper (X40). The assignment of the jumper to the contact
type and the arrangement of the jumper are described in the following section under the margin heading „In-
put/output module C-I/O-10“.
Nominal currents
The input transformers of the device are set to a nominal current of 1 A or 5 A by burden switching. The jumpers
are factory set according to the name-plate sticker. The assignment of the jumpers to the nominal current and
the spatial arrangement of the jumpers are described in the following section under the margin heading „In-
put/output module C-I/O-2“. All jumpers must be set for one nominal current, i.e. one jumper (X61 to X64) for
each input transformer and additionally the common jumper X60.