Impacts On The Functionality Of The Device - Siemens siprotec SJ62 User Manual

2.24.2 Impacts on the Functionality of the Device

Undervoltage Pro-
tection, Overvolt-
age Protection (27,
59 Elements)
Frequency Protec-
tion (81 Elements)
Directional Time
Overcurrent Pro-
tection (67 and 67N
Elements)
Synchronism and
Voltage Check (25)
(7SJ64 only)
SIPROTEC 4, 7SJ62/63/64 Handbuch
C53000-G1140-C147-A, Edition 07.2015
2.24 Protection for Single-phase Voltage Transformer Connection
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. Further-
more, this type of connection is dealt with in the functional descriptions. Functions not
mentioned in the following are not affected by this type of connection.
Depending on the configuration in address 240 voltage protection is either operated
by a phase-ground or a phase-phase voltage. Therefore, if the device is connected to
a phase-ground voltage, set the phase voltage threshold. If connected to a phase-
phase voltage, set the phase-to-phase voltage threshold. In contrast, 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.
Depending on the configuration in address 240 frequency protection is either operat-
ed by a phase-ground or a phase-phase voltage. A minimum voltage may be config-
ured. If the value set is undershot, frequency protection is blocked. Therefore, if the
device is connected to a phase-ground voltage, set the phase voltage threshold. If
connected to a phase-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.
If the device is connected to only one voltage transformer, the function is set to inactive
and hidden.
The synchronizing function can be applied without any restrictions. Connection exam-
ples are shown in the following figure and in the Appendix A.3.
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