Settings - Siemens SIPROTEC 4 7SD80 Manual

Line differential protection
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Functions
2.1 General
If the input Ι
Address 220 I4 transformer = Not connected,
Address 221 I4/Iph CT is then irrelevant.
In this case, the neutral current is calculated by summing the phase currents.
Rated Frequency
The rated frequency of the system is set at address 230 Rated Frequency. The factory setting of the model
variant must only be changed if the device is to be used for a purpose other than intended when ordering. You
can set 50 Hz or 60 Hz.
System Starpoint
The manner in which the system neutral point is grounded must be considered for the correct processing of
ground faults and double ground faults. Accordingly, set address 207 SystemStarpoint = Grounded,
Peterson-C.Gnd. or Isolated. For low-resistance or high-resistance ("impedance grounded") systems, set
Grounded.
Depending on the setting of this parameter, the ground fault differential protection uses either the measured
ground current (Grounded) or the values calculated from the power values (Peterson-C.Gnd. or
Isolated).
Command Duration
In address 240 the minimum trip command duration TMin TRIP CMD is set. It applies to all protection and
control functions that can initiate a trip command. It also determines the duration of the trip pulse when a
circuitbreaker trip test is initiated via the device. This parameter can only be set in DIGSI under Display Addi-
tional Settings.
In address 241 the maximum close command duration TMax CLOSE CMD is set. This applies to all close
commands issued by the device. It also determines the length of the close command pulse when a circuit-
breaker test cycle is issued via the device. It must be long enough to ensure that the circuit breaker has
securely closed. An excessive duration causes no problem since the closing command is interrupted in the
event that another trip is initiated by a protection function. This parameter can only be set in DIGSI under
Display Additional Settings.
Circuit-Breaker Test
7SD80 allows a circuit-breaker test during operation using a trip-and-close command entered on the front
panel or from DIGSI. The duration of the trip command is set as explained above. Address 242 T-CBtest-dead
determines the duration from the end of the trip command until the start of the close command for this test. It
should not be less than 0.1 s.
Pickup Thresholds of the Binary Inputs (BI Thresholds)
At addresses 260 Threshold BI 1 to 266 Threshold BI 7 you can set the pickup thresholds of the
binary inputs of the device. The settings Thresh. BI 176V, Thresh. BI 88V or Thresh. BI 19V are
possible here.
2.1.3.2

Settings

Addresses which have an appended "A" can only be changed with DIGSI, under "Additional Settings".
Addr.
Parameter
201
CT Starpoint
203
Vnom PRIMARY
204
Vnom SECONDARY
205
CT PRIMARY
38
is not required, set:
4
Setting Options
towards Line
towards Busbar
0.4 .. 500.0 kV
80 .. 125 V
10 .. 20000 A
Default Setting
Comments
towards Line
CT Starpoint
10.0 kV
Rated Primary Voltage
100 V
Rated Secondary Voltage (Ph-Ph)
400 A
CT Rated Primary Current
E50417-G1100-C474-A2, Edition 02.2018
SIPROTEC 4, 7SD80, Manual

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