2.1 General
55
7SA522 Manual
C53000-G1176-C155-3
In the former case the synchronism check function must be configured as available, a
busbar voltage must be connected to the device and this must be correctly parame-
terized in the power system data (Section 2.1.3.1, address 8WUDQVIRUPHU =
8V\QFWUDQVI, as well as the the associated factors).
If no synchronism check is to be performed with manual closing, set 0$1&/26( =
ZR6\QFFKHFN. If a check is desired, set ZLWK6\QFFKHFN. To not use the
MANUAL CLOSE function of the device at, set 0$1&/26( to 12. This may be rea-
sonable if the close command is output to the circuit breaker without involving the
7SA522 and the relay itself is not desired to issue a close command.
For commands via the integrated control (local control, DIGSI, serial interface)
address 0DQ&ORV,PS determines whether a particular close command via
the integrated control function should be treated by the protection (like instantaneous
re-opening when switching onto a fault) like a MANUAL CLOSE command via binary
input. This address also tells the device for which switchgear this applies. You can
select from the switching devices which are available for the integrated control.
Choose that circuit breaker which usually operates for manual closure and, if required,
for automatic reclosure (usually Q0). If QRQH is set here, a CLOSE command via the
control will not generate a MANUAL CLOSE impulse for the protection function.
Address 5HVHW7ULS&0' determines under which conditions a trip command
is reset. If &XUUHQW2SHQ3ROH is set, the trip command is reset as soon as the current
disappears. It is important that the value set in address 3ROH2SHQ&XUUHQW
(see above) is undershot. If &XUUHQW$1'&% is set, the circuit-breaker auxiliary
contact must send a message that the circuit breaker is open. It is a prerequisite for
this setting that the position of the auxiliary contacts is allocated via a binary input.
Three-pole
Coupling
Three-pole coupling is only relevant if single-pole auto-reclosures are carried out. If
not, tripping is always three-pole. The remainder of this margin heading section is then
irrelevant.
Address SROHFRXSOLQJ determines whether any multi-phase pickup
leads
to a three-pole tripping command, or whether only multi-pole tripping
decisions result
in a three-pole tripping command. This setting is only relevant with one- and three-pole
tripping and therefore only available in this version. More information on this functions
is also contained in Subsection 2.20.1 Pickup Logic for the Entire Device.
With the setting ZLWK3,&.83 every fault detection in more than one phase leads to
three-pole coupling of the trip outputs, even if only a single-phase earth fault is situated
within the tripping region, and further faults only affect the higher zones, or are located
in the reverse direction. Even if a single-phase trip command has already been issued,
each further fault detection will lead to three-pole coupling of the trip outputs.
If, on the other hand, this address is set to ZLWK75,3, three-pole coupling of the trip
output (three-pole tripping) only occurs when more than one pole is tripped. Therefore
if a single-phase fault is located within the zone of tripping, and a further arbitrary fault
is outside the tripping zone, single-phase tripping is possible. Even a further fault
during the single-pole tripping will only cause three-pole coupling if it is located within
the tripping zone.
This parameter is valid for all protection functions of 7SA522 which are capable of
single-pole tripping.
The difference made by this parameter becomes apparent when multiple faults are
cleared, i.e. faults occurring almost simultaneously at different locations in the net-
work.
If, for example, two single-phase ground faults occur on different lines — these may
also be parallel lines — (Figure 2-5), the protective relays of all four line ends detect a
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