Technical Data
4.9 Circuit-Breaker Failure Protection (Optional)
SIPROTEC, 7SD80, Manual
E50417-G1140-C474-A1, Release date 09.2011
310
4.9 Circuit-Breaker Failure Protection (Optional)
Circuit Breaker Supervision
Initiation Conditions
1)
Via binary inputs
Times
End Fault Protection
Pole Discrepancy Supervision
Current-flow Monitoring for I
Nom
= 1 A 0.05 A to 20.00 A Increments 0.01 A
for I
Nom
= 5 A 0.25 A to 100.00 A
Zero sequence current monitoring for I
Nom
= 1 A 0.05 A to 20.00 A Increments 0.01 A
for I
Nom
= 5 A 0.25 A to 100.00 A
Dropout ratio approx. 0.95
Tolerance 5 % of setting value or 1 % of nominal current
Monitoring of circuit breaker auxiliary contact position
for three-pole tripping binary input for CB auxiliary contact
Note
:
The circuit breaker failure protection can also operate without the indicated circuit breaker auxiliary contacts, but the func-
tion range is then reduced.
Auxiliary contacts are necessary for the circuit breaker failure protection for tripping without or with a very low current flow
(e.g. Buchholz protection) and for stub fault protection and circuit breaker pole discrepancy supervision.
For circuit breaker failure protection Internal or external 1-pole trip
1)
Internal or external 3-pole trip
1)
Internal or external 3-pole trip without current
1)
Pickup time Approx. 5 ms with measured quantities present
Approx. 20 ms after switch-on of measured quantities
Drop-off time, internal (overshoot time) ≤ 15 ms at sinusoidal measured values,
≤ 25 ms maximal
Time delays for all elements 0.00 s to 30.00 s; ∞ Increments 0.01 s
Tolerance 1 % of setting value or 10 ms
With signal transmission to the opposite line end
Time delay 0.00 s to 30.00 s; ∞ Increments 0.01 s
Tolerance 1 % of setting value or 10 ms
Initiation criterion Not all poles are closed or open
Monitoring time 0.00 s to 30.00 s; ∞ Increments 0.01 s
Tolerance 1 % of setting value or 10 ms