Supervisory Functions
153
7SS52 V4 Manual
C53000-G1176-C182-3
Permanent monitoring of the program flow
by means of watchdog (BU, CU)
After three unsuccessful restart attempts the
protection is blocked.
Differential current supervision
•
Bus zone-selective protection
| Σ
I
|
(
6308/CU
)
for T >
)
•
Check zone, all except bus coupler
| Σ
I
|
6309/CU
)
for T >
CU
)
Current transformer circuit faulty
Bus zone-selective blocking
if the parameter
CU
) is set to blocking, otherwise only alarm
"
IdSup Lz-y $03
"
(
FNo. 177.1321
177.1322, 177.1323, 177.1326,
177.1327, 177.1328/CU
)
Blocking if the parameter
) is set to
blocking, otherwise only alarm
"
Id-Sup CZ Lz
" (
FNo. 10411, 10412,
10413/CU
)
Monitoring of isolator status
•
Running position
Isolator OPEN/CLOSED = 0/0
for T >
(
/
CU
)
•
Auxiliary voltage supply failure
All isolator positions
of one bay = 0/0
•
Implausible isolator status
Isolator OPEN/CLOSED = 1/1
Wire break or intermediate status
Alarm "
FltR $01 $02
"
(
FNo. 176.1112, 176.1117, 176.1122,
)
Feeder aux. voltage MCB tripped
Alarm "
BayDC fail $00
"
(
)
Alarm "
FltP $01 $02
"
(
FNo. 176.1113
,
)
Cyclic check of the
data transmission links (FO) between
central unit and bay unit
Blocking of the protection system and alarm
after two recognitions of a transmission error
"
Fail Com.CU
"
(
FNo. 7650/BU
)
Monitoring of
"
>CBF Lx
", "
>CBF 3-pole
"
for T > 15 s
"
>CBF Lx
", "
>CBF 3-pole
" and
"
>CBF release
", "
>release 3-pole
"
(
XX28/CU
)
"
>CBF release
", "
>release 3-pole
"
for T >
XX27/CU
)
"
>B.U.CBF Lx
"
,
"
>B.U.CBF 3-pole
"
for T =
B.U.CBF-T
(
3912/BU
) + 5 s
(but min. 15 s)
Alarm and blocking of the binary
input of the affected feeder
"
BF-BIErr $00 Lz
" (
FNo. 176.1091
/
CU
) or
"
BF-BIErr $00 3P
" (
FNo. 176.1094
/
CU
);
Supervision picks up if a signal is present at
the BI BF-phase for the time T > 15s;
Supervision picks up if both BI BF-phase and
BI BF release do not arrive within the time win-
dow T = limit;
Alarm and blocking of CBF
"
BFRlErr $01 1P
" (
FNo. 176.1101/CU
)
or
"
BFRlErr $00 3P
" (
FNo. 176.1102/CU
)
Cyclic test with simulation of a fault current
and monitoring of the entire signal process-
ing from the digitized measured values to
the control currents of the trip relay coils
After three recognitions of an error blocking of
the protection and alarm.
"
Flt aut $00
" (
FNr. 176.1190
/
CU
)
and
"
Flt autotest M
" (
FNr. 10429
/
CU
)
Zero current monitoring
Monitoring is done phase-selectively and the
alarm "
Block ZeroCross
" (
FNo. 10444/
CU
) is generated.
Monitoring
Possible cause and response
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