Siemens siprotec 7SD5 User Manual

2 Functions
390
7SD5 Manual
C53000-G1176-C169-1
Circuit Breaker for
Voltage Transform-
ers
If a circuit breaker for voltage transformers (VT mcb) is installed in the secondary
circuit of the voltage transformers, the status is sent, via binary input, to the device in-
forming it about the position of the VT mcb. If a short-circuit in the secondary side ini-
tiates the tripping of the VT mcb, the distance protection function has to be blocked
immediately, since otherwise it would be spuriously tripped due to the lacking mea-
sured voltage during a load current. The blocking must be faster than the first stage of
the distance protection. This requires an extremely short reaction time for VT mcb
(≤ 4 ms at 50 Hz, ≤ 3 ms at 60 Hz nominal frequency). If this cannot be ensured, the
reaction time is to be set under address 2921 T mcb; this, however, will delay the re-
sponse of the protection function.
2.22.1.6 Settings
Addresses which have an appended "A" can only be changed with DIGSI, under Ad-
ditional Settings.
The table indicates region-specific presettings. Column C (configuration) indicates the
corresponding secondary nominal current of the current transformer.
Addr. Parameter C Setting Options Default Setting Comments
2901 MEASURE. SUPERV ON
OFF
ON Measurement Supervision
2902A BALANCE U-LIMIT 10 .. 100 V 50 V Voltage Threshold for
Balance Monitoring
2903A BAL. FACTOR U 0.58 .. 0.95 0.75 Balance Factor for Voltage
Monitor
2904A BALANCE I LIMIT 1A 0.10 .. 1.00 A 0.50 A Current Balance Monitor
5A 0.50 .. 5.00 A 2.50 A
2905A BAL. FACTOR I 0.10 .. 0.95 0.50 Balance Factor for Current
Monitor
2906A ΣI THRESHOLD 1A 0.10 .. 2.00 A 0.25 A Summated Current Moni-
toring Threshold
5A 0.50 .. 10.00 A 1.25 A
2907A ΣI FACTOR 0.00 .. 0.95 0.50 Summated Current Moni-
toring Factor
2908A T BAL. U LIMIT 5 .. 100 sec 5 sec T Balance Factor for
Voltage Monitor
2909A T BAL. I LIMIT 5 .. 100 sec 5 sec T Current Balance Monitor
2910 FUSE FAIL MON. ON
OFF
ON Fuse Failure Monitor
2911A FFM U>(min) 10 .. 100 V 30 V Minimum Voltage Thresh-
old U>
2912A FFM I< (max) 1A 0.10 .. 1.00 A 0.10 A Maximum Current Thresh-
old I<
5A 0.50 .. 5.00 A 0.50 A
2913A FFM U<max (3ph) 2 .. 100 V 5 V Maximum Voltage Thresh-
old U< (3phase)
2914A FFM Idelta (3p) 1A 0.05 .. 1.00 A 0.10 A Delta Current Threshold
(3phase)
5A 0.25 .. 5.00 A 0.50 A
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Siemens siprotec 7SD5 Specifications

General

Brand	Siemens
Model	siprotec 7SD5
Category	Relays
Language	English