Siemens siprotec SJ62 User Manual page 47

2 Functions
Voltage Connection
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Figure 2-2 Polarity of current transformers
Address 213 specifies how the voltage transformers are connected. VT Connect.
3ph = Van, Vbn, Vcn means that three phase voltages in wye-connection are con-
nected, VT Connect. 3ph = Vab, Vbc, VGnd signifies that two phase-to-phase
voltages (V-connection) and V
only two phase-to-phase voltage transformers are utilized or when only the displaced
voltage (zero sequence voltage) is connected to the device.
Device 7SJ64 contains 4 voltage measuring inputs which enable further options
besides the above-mentioned connection types: VT Connect. 3ph =
Van,Vbn,Vcn,VGn is selected if the three phase voltages in wye-connection and V
are connected to the fourth voltage input of the device. Select VT Connect. 3ph =
Van,Vbn,Vcn,VSy in case the fourth voltage input is used for the synchronizing
function even if two phase-to-phase voltages (V-connection) are available on the
primary side (since the voltages are connected to the device such that the device mea-
sures phase-ground voltages under symmetrical conditions).
Note
If the synchronization function is used for the connection to two-phase-to-phase volt-
ages in V-connection (see above), the device cannot determine a zero sequence volt-
age. The function „Directional Time Overcurrent Ground Protection", „Directional
Ground Fault Detection" and „Fuse-Failure-Monitor (FFM)" must be disabled.
Parameter 240 VT Connect. 1ph is set to specify that only one voltage transformer
is connected to the devices. In this case the user defines which primary voltage is con-
nected to which analog input. If one of the available voltages is selected, i.e. a setting
unequal NO, setting of address 213 is no more relevant. Only address 240 is to be set.
If parameter 240 VT Connect. 1ph is set to NO on the other hand, parameter 213
will apply.
With 7SJ64 and single-phase voltage transformer connection the voltage connected
to voltage input V is always interpreted as the voltage which is to be synchronized.
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are connected. The latter setting is also selected when
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SIPROTEC 4, 7SJ62/63/64 Handbuch
C53000-G1140-C147-A, Edition 07.2015
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