Current flow monitoring 212
BkrClosed I MIN
, which some protective functions rely upon to detect a
closed CB, is used as the current zero criterion. It should be set with respect to the actually used device func-
tions (see also margin heading “Current Flow Monitoring (CB)” in Section
.
Σ
Ι
Procedure
Being the basic function of summation current formation, the Σ
Ι
-procedure is always active and does not
require any additional settings. This is irrespective of the configuration in address 172
52 B.WEAR MONIT
.
This method does not offer integrated threshold evaluation. The latter could, however, be implemented using
CFC.
Σ
Ι
x
-Procedure
Parameter 172
52 B.WEAR MONIT
can be set to activate the Σ
Ι
x
procedure. In order to facilitate evaluating
the sum of all tripping current powers, the values are referred to the involuted CB rated operational current.
This value is indicated in the CB data at address 260
Ir-52
in the
P.System Data 1
and can be set as
primary value. This reference allows the threshold of the Σ
Ι
x
procedure to correspond to the maximum
number of make-break operations. For a circuit breaker, whose contacts have not yet been worn, the
maximum number of make-break operations can be entered directly as threshold. The exponent for the invo-
lution of the rated operational current and of the tripping currents is set at address 264
Ix EXPONENT
. To
meet different customer requirements, this exponent 264
Ix EXPONENT
can be increased from
1.0
(default
setting =
2.0
) to 3.0.
For the procedure to operate correctly, the time response of the circuit breaker must be specified in parame-
ters 2266
T 52 BREAKTIME
and 267
T 52 OPENING
.
The summated values can be interpreted as the number of tripping operations at rated operational current of
the CB. They are displayed in the statistical values without unit and with two decimal places.
2P-Procedure
Parameter 172
52 B.WEAR MONIT
can be set to activate the 2P procedure. An operating cycles diagram (see
sample diagram in the functional description of the 2P procedure), provided by the manufacturer, shows the
relationship of make-break operations and tripping current. The two vertices of this characteristic in a double
logarithmic scale are decisive for the setting of addresses 260 to 263:
Point P1 is determined by the number of permitted make-break operations (parameter 261
OP.CYCLES AT
Ir
) for rated operational current
Ι
r (parameter 260
Ir-52
)
Point P2 is determined by the maximum number of make-break operations (parameter 263
OP.CYCLES Isc
)
for rated fault tripping current
Ι
sc (parameter 262
Isc-52
).
For the procedure to operate correctly, the time response of the circuit breaker must be specified in parame-
ters 266
T 52 BREAKTIME
and 267
T 52 OPENING
.
Ι
2
t-Procedure
The
Ι
2
t-procedure is activated via configuration parameter 172
52 B.WEAR MONIT
. The square fault current
integrals are referred to the squared device nominal current. For purposes of determining the arc time, the
device must be informed of the CB tripping time
T 52 BREAKTIME
as well as the CB opening time
T 52
OPENING
of the circuit breaker. For recognition of the last zero crossing (arc deletion) of the currents after
tripping, the “Current-zero” Criterion is required.
Information List
No.
Information
Type of
Informa-
tion
Comments
-
#of TRIPs=
PMV
Number of TRIPs=
409
>BLOCK Op Count
SP
>BLOCK Op Counter
1020
Op.Hours=
VI
Counter of operating hours
1021
Σ Ia =
VI
Accumulation of interrupted current Ph A
2.25.2.5
Functions
2.25 Auxiliary Functions
328
SIPROTEC 4, 7SJ62/64, Manual
C53000-G1140-C207-8, Edition 08.2016
Summary of Contents for SIPROTEC 4
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