Siemens SIPROTEC 7SJ80

Table 2-1 Connection Types of the Voltage Transformers
Connection
type
Functions
Directional
definite
time/
inverse time
overcurrent
protection
phase
Directional
definite-
time/ inver-
setime over-
current
protection
ground
Sensitive
ground fault
protection
50Ns, 51Ns,
67Ns
Synchroni-
zation
Fault
locator
QU
protec-
tion
Direc-
tional
intermit-
tent
ground
fault
Fuse
failure
monitor
Van, Vbn,
Vcn
yes yes yes no yes yes yes yes
Vab, Vbc,
VGnd
yes yes yes no yes yes yes yes
Vab, Vbc
yes
yes
1)
yes
2)
no no yes no no
Vab, Vbc, Vx
yes
yes
1)
yes
2)
no no yes no no
Vab, Vbc,
VSyn
yes no
yes
2)
yes no yes no no
Vph-g, VSyn
no no
yes
2)
yes no no no no
1)
Determination of the direction is only possible by evaluating the negative sequence system (otherwise select zero
sequence system or negative sequence system).
2)
With this type of voltage transformer connection the current elements operate only non-directional, the voltage
elements do not work.
With voltage connections Vab, Vbc, Vab, Vbc, Vx and Vab, Vbc, VSyn the power values are only
available if you have symmetrical voltage conditions within the network. In this case, address 207 Vol.
Symmetry (Power System Data 1) is set to YES. The power values are not available with setting NO.
Measured values, which due to the chosen voltage connection cannot be calculated, will be displayed as dots.
The Appendix provides some connection examples for all connection types atC Connection Examples.
Distance Unit (Power System)
Address 215 Distance Unit allows you to specify the distance unit (km or Miles) for the fault locator. In
the absence of a fault locator or if this function has been removed, this parameter is of no importance.
Changing the distance unit does not imply an automatic conversion of the setting values that are dependent
on the distance unit. These have to be re-entered at the respective addresses.
ATEX100 (Power System)
Parameter 235 ATEX100 enables meeting the requirements for protecting explosion-protected motors for
thermal replicas. Set this parameter to YES to save all thermal replicas of the 7SJ80 devices in the event of a
power supply failure. After the supply voltage is restored, the thermal replicas will resume operation using the
stored values. Set the parameter to NO, to reset the calculated overtemperature values of all thermal replicas
to zero if the power supply fails.
Nominal Values of Current Transformers (CTs)
At addresses 204 CT PRIMARY and 205 CT SECONDARY, information is entered regarding the primary and
secondary ampere ratings of the current transformers. It is important to ensure that the rated secondary
current of the current transformer matches the rated current of the device, otherwise the device will calculate
incorrect primary data. At addresses 217 Ignd-CT PRIM and 218 Ignd-CT SEC, information is entered
regarding the primary and secondary ampere rating of the current transformer. In case of a normal connection
(neutral point current connected to Ι
N
transformer), 217 Ignd-CT PRIM and 204 CT PRIMARY must be set
to the same value.
If the device features a sensitive ground current input, parameter 218 Ignd-CT SEC is set to 1 A by default.
In this case, the setting cannot be changed.
Functions
2.1 General
SIPROTEC 4, 7SJ80, Manual 41
E50417-G1140-C343-A8, Edition 12.2017