ABB REC 561 User Manual page 263

1MRK 580 171-XEN
Page 5 - 84
Start BFP
Relay
time
30ms
Breaker-failure protection
The application functions of the protection are:
• Individual phase-current detection
• Two time steps, one for retrip of the related circuit breaker and one
for the back-up trip of the adjacent circuit breakers
• Selection of current controlled or unconditional retrip
• Phase separated timers correct timing at an evolving fault
• Accurate timers and current elements reset in 10 ms, allowing the
use of short back-up trip time
Normal
CB opening
Marginal
CB opening time
40ms
Fig. 2
20ms
BFP
time
CB opening time
<10ms
Time sequence
ABB Network Partner AB
Retrip
original CB
110ms
40ms
Marginal
20ms
Version 1.0-00
General trip
adjacent CB
150ms
BFP
time
<10ms
(X80171-2)