Functions
2.24 Protection for Single-phase Voltage Transformer Connection
SIPROTEC, 7SJ62/64, Manual
C53000-G1140-C207-2, Release date 01.2008
374
2.24.2
Impacts on the Functionality of the Device
When a device is operated by only one voltage transformer, this will have an impact on several device functions.
The ones affected are described in the following. Furthermore, this type of connection is dealt with in the func-
tional descriptions. Functions not mentioned in the following are not affected by this type of connection.
Undervoltage Protection, Overvoltage Protection (27, 59 Elements)
Depending on the configuration in address
240
voltage protection is either operated by a phase-to-ground or
a phase-to-phase voltage. Therefore, if the device is connected to a phase-to-ground voltage, set the phase
voltage threshold. If connected to a phase-phase voltage, set the phase-to-phase voltage threshold. In con-
trast, with three-phase connection, the threshold generally represents a phase-to-phase quantity. See also
Section 2.6.4.
Functional logic, scope of settings and information of this function are described in Section 2.6.
Frequency Protection (81 Elements)
Depending on the configuration in address
240
, frequency protection is either operated by a phase-to-ground
or a phase-to-phase voltage. A maximum voltage may be configured. If the value set is undershot, frequency
protection is blocked. Therefore, if the device is connected to a phase-to-ground voltage, set the phase voltage
threshold. If connected to a phase-to-phase voltage, set the phase-to-phase voltage threshold.
Functional logic, scope of settings and information of this function are described in Section 2.9.
Directional Time Overcurrent Protection (67 and 67N Elements)
If the device is connected to only one voltage transformer, the function is set to inactive and hidden.
Synchronization
The synchronization function can be applied without any restrictions. Connection examples are shown in the
following figure and in the Appendix, Subsection A.3.
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