the available voltages is selected, that is a setting unequal NO, setting of address 213 is not relevant anymore.
Only the setting of parameter 240 is relevant. If on the contrary parameter240 VT Connect. 1ph is set to
NO, parameter 213 applies.
Chapter 2.26 Protection for Single-phase Voltage Transformer Connection describes the effect of the single-
phase voltage transformer connection on the individual protection functions.
For the devices 7SJ623, 7SJ624, 7SJ625, 7SJ626 and 7SJ64 with single-phase voltage transformer connection,
the voltage applying at voltage input V
4
is generally interpreted as the voltage to be synchronized.
NOTE
If the synchronization function is used in a connection of two phase-to-phase voltages in open delta
voltage (see above), the device is unable to determine a zero sequence voltage. The functions “Directional
Time Overcurrent Protection Ground”, “Directional Ground Fault Detection” and “Fuse Failure Monitoring
(FFM)” must be either removed or switched off.
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 7SJ62/64 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.
If address 251 has been set so that ground currents are measured by two inputs (setting options A,G2,C,G;
G->B or A,G2,C,G; G2->B), you have to set the primary rated current of the second ground transformer
connected to Ι
N2
at address 238. secondary ampere rating must conform with the phase current transformer.
To calculated the phase current Ι
B
correctly, the primary rated current of the ground current transformer,
which is used to calculate Ι
B
(address 217 or address 238), must be smaller than the primary rated current of
the phase current transformer (address 204).
Nominal Values of Voltage Transformers (VTs)
At addresses 202 Vnom PRIMARY and 203 Vnom SECONDARY, information is entered regarding the primary
nominal voltage and secondary nominal voltage (phase-to-phase) of the connected voltage transformers.
Transformation Ratio of Voltage Transformers (VTs)
Address 206 Vph / Vdelta informs the device of the adjustment factor between the phase voltage and the
displacement voltage. This information is relevant for the processing of ground faults (in grounded systems
and ungrounded systems), for the operational measured value V
N
and measured-variable monitoring.
Functions
2.1 General
44 SIPROTEC 4, 7SJ62/64, Manual
C53000-G1140-C207-8, Edition 08.2016
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