Circuit-Breaker Failure Protection 3-Pole
Starting Conditions
For circuit-breaker failure protection
3-pole tripping internal or external
35
Setting Values
Phase-current threshold
values
1 A @ 100 Irated
0.030 A to 35.000 A
Increments of 0.001 A
5 A @ 100 Irated
0.15 A to 175.00 A
Increments of 0.01 A
Sensitive threshold value 1 A @ 100 Irated
0.030 A to 35.000 A
Increments of 0.001 A
5 A @ 100 Irated
0.15 A to 175.00 A
Increments of 0.01 A
Supervision time of release signal
0.00 s to 1.00 s
Increments of 0.01 s
Time delays T1
0.000 s to 60.000 s
Increments of 0.001 s
Time delays T2
0.050 s to 60.000 s
Increments of 0.001 s
Supervision times of the binary inputs
0.05 s to 60.00 s
Increments of 0.01 s
Dropout
The greater dropout differential (=
| pickup threshold – dropout threshold |
) of the following
2 criteria applies:
Dropout differential derived from the parameter
Dropout ratio
If this parameter is not available, a dropout ratio of 95 % applies to the current threshold values.
Minimum absolute dropout differential
Protection-class current transformers
15 mA sec. (I
rated
= 1 A) or
75 mA sec. (I
rated
= 5 A)
Instrument transformers
0.5 mA sec. (I
rated
= 1 A) or
2.5 mA sec. (I
rated
= 5 A)
Circuit-Breaker Supervision
Position supervision via circuit-breaker auxiliary contacts
For 3-pole CB tripping
1 input each for make contact and break contact
i
i
NOTE
The circuit-breaker failure protection can also work without the circuit-breaker auxiliary contacts stated.
Auxiliary contacts are required for circuit-breaker failure protection in cases where the current flow is
absent or too low for tripping (for example with a transformer or a Buchholz protection).
Times
Pickup time, in the case of an internal start
Pickup time, in the case of an external start
< 1 ms
< 5 ms
Dropout time for unbalancing operating mode
Approx. 2 ms
Typical dropout time
< 15 ms
Dropout time, via circuit-breaker auxiliary contact
criterion
< 5 ms
11.5
35
Via binary inputs
Technical Data
11.5 Circuit-Breaker Failure Protection 3-Pole
SIPROTEC 5, Low-Impedance Busbar Protection, Manual
917
C53000-G5040-C019-C, Edition 04.2021