Siemens 6MD85, Manual

Page: 1167 / 1256

Circuit-Breaker Failure Protection
Starting Conditions
For circuit-breaker failure protection
3-pole tripping internal or external 84
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
1 A @ 1.6 Irated 0.001 A to 1.600 A Increments of 0.001 A
5 A @ 1.6 Irated 0.005 A to 8.000 A Increments of 0.001 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
1 A @ 1.6 Irated 0.001 A to 1.600 A Increments of 0.001 A
5 A @ 1.6 Irated 0.005 A to 8.000 A Increments of 0.001 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
Monitoring 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 95 % of the pickup value
Minimum absolute dropout differential
Protection-class current transformer
15 mA sec. (I
rated
= 1 A) or
75 mA sec. (I
rated
= 5 A)
Instrument current transformer 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
Typical dropout time < 15 ms
Dropout time via circuit-breaker auxiliary contact
criterion < 5 ms
11.28
84 Via binary inputs
Technical Data
11.28 Circuit-Breaker Failure Protection
SIPROTEC 5, High-Voltage Bay Controller, Manual 1167
C53000-G5040-C015-9, Edition 11.2017