Functions
154
7SS52 V4 Manual
C53000-G1176-C182-3
5.5.2
The parameter
) is used to select the blocking mode of
the busbar and breaker failure protection in the event of
•
Measured value errors
•
Failure of a bay unit
•
Isolator malfunctions (
6302/CU
)
With setting
3-pole or 1-pole blocking is only performed on the protec-
tion zone allocated to the bay unit. If zone-selective blocking is performed on a 1-bay
coupler, both affected protection zones will be blocked.
With setting
the protection will be blocked completely.
The parameter
6306/CU
) is used to activate and deactivate the dif-
ferential current supervision.
With setting
the differential current supervision will be activated. In normal mode
the differential current supervision must remain ON.
With setting
the differential current supervision will be deactivated. The differen-
tial current supervision may be deactivated for testing (e.g. for establishing the char-
acteristic).
The parameter
6307/CU
) is used to set the delay time for block-
ing or alarm after a pickup of the differential current supervision.
The parameter
6308/CU
) is used to set the threshold I/Ino for se-
lective differential current supervision.
The parameter
6309/CU
) is used to set the threshold I/Ino for dif-
ferential current supervision in the check zone.
The monitoring limit value should be set as low as possible, generally to the double
maximum differential current in fault-free condition. Please note that due to the fault
characteristic of the current transformers, there usually occur more severe faults un-
der weak-infeed conditions than under rated load.
Battery monitoring of central units and bay
units
Alarm is generated for the bay unit with
"
BattSuperv $00
" (
FNo. 176.1174/CU
)
and for the central unit with
"
Batt. superv CU
" (
FNo. 10422/CU
) and
group alarm "
Err PROT ACTIVE
"
(
FNo. 10475/CU
)
Cyclic monitoring of the parameter/configu-
ration data of the central units and bay units
A fault buffer entry is made and a restart car-
ried out. After two unsuccessful attmpts: fault
Monitoring of CB-feedback
no plausible State
CB OPEN/CLOSED = 0/0 or 1/1
Alarm: "
CB fault $01
”
(
FNo. 176.1135/CU
) and (
FNo.
176.1136/CU
) Blocking of end fault protec-
tion and low-current mode of breaker failure
protection.
Monitoring
Possible cause and response
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