2 Functions
248
7SA522 Manual
C53000-G1176-C155-3
Table 2-7 In 7SA522 this concerns:
For the functions which are to start the auto-reclosure function, the corresponding
address is set to <(6, for the others to 12. The other functions (overload protection,
frequency protection, breaker failure protection) cannot start the automatic reclosure
because reclosure is of little use here.
Forced Three-pole
Trip
If reclosure is blocked during the dead time of a single-pole cycle without a three-pole
trip command having been initiated, the breaker remains open at one pole. With
address $575,3SROH it is possible to determine that the tripping logic of the
device issues a three-pole trip command in this case (pole discrepancy prevention for
the CB poles). Set this address to <(6 if the CB can be tripped single-pole and has no
pole discrepancy protection itself. Nevertheless, the device pre-empts the pole dis-
crepancy supervision of the CB because the forced three-pole trip of the device is im-
mediately initiated as soon as the reclosure is blocked following a single-pole trip or if
the CB auxiliary contacts report an implausible breaker state (see also Subsection
2.13 at margin heading “Processing the Circuit Breaker Auxiliary Contacts”). The
forced three-pole coupling is also activated when only three-pole cycles are allowed
but a single-pole trip is signalled externally via a binary input.
The forced three pole trip is unnecessary if only a common three-pole control of the
CB is possible.
Dead Line Check /
Reduced Dead
Time
Under address the dead line check or the reduced dead time function can be
activated. Either the one or the other can be used as the two options are contradictory.
The voltage transformers must be connected to the line side of the circuit breaker if
either of these modes is to be used. If this is not the case or if neither of the two func-
tions is used, set '/&RU5'7 = :,7+287. If the adaptive dead time is used (see
below), the parameters mentioned here are omitted because the adaptive dead time
implies the properties of the reduced dead time.
'/&RU5'7 = '/& means that the dead line check of the line voltage is used. This
only enables reclosure after it becomes apparent that the line is dead. In this case, the
phase-earth voltage limit is set in address 8GHDG below which the line is con-
sidered voltage-free (disconnected). The setting is applied in Volts secondary. This
value can be entered as a primary value when parameterizing with a PC and DIGSI
®
.
Address 78VWDEOH determines the measuring time available for determining
the no-voltage condition. Address is irrelevant here.
'/&RU5'7 = 5'7 means that the reduced dead time is used. This is described in
detail in Section 2.13 at margin heading “Reduced Dead Time (RDT)”. In this case the
setting under address 8OLYH! determines the limit voltage, Phase–Earth,
above which the line is considered to be fault-free. The setting must be smalIer than
the lowest expected operating voltage. The setting is applied in Volts secondary. This
value can be entered as a primary value when parameterizing with a PC and DIGSI
®
.
Address 78VWDEOH determines the measuring time used to determine that
the line is fault free with this return voltage. It should be longer than any transient os-
cillations resulting from line energization. Address is irrelevant here.
Address 3420 AR w/ DIST., i.e. with distance protection
Address 3421 AR w/ SOTF-O/C, i.e. with high-current fast tripping
Address 3422 AR w/ W/I, i.e. with weak–infeed trip function
Address 3423 AR w/ EF-O/C, i.e. with transfer trip and remote trip
Address 3424 AR w/ DTT, i.e. with externally fed trip command
Address 3425 AR w/ BackUpO/C, i.e. with time overcurrent protection
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