ABB Relion 670 Series Applications Manual page 223

1MRK 505 370-UUS Rev. K
7.10.3.1 Restrike detection
Opening of SCBs can be quite problematic for certain types of circuit breakers (CBs). Typically such
problems are manifested as CB restrikes.
In simple words this means that the CB is not breaking the current at the first zero crossing after
separation of the CB contacts. Instead current is re-ignited and only braked at consecutive current zero
crossings. This condition is manifested as high current pulses at the moment of current re-ignition.
To detect this CB condition, the built in overcurrent feature can be used. Simply, any start of the
overcurrent feature during breaker normal opening means a restrike. Therefore simple logic can be
created in the Application Configuration tool to detect such CB behavior. Such CB condition can be just
alarmed, and if required, the built in disturbance recorder can also be triggered.
To create this logic, a binary signal that the CB is going to be opened (but not trip command) shall be
made available to the IED.
Busbar protection REB670
Application manual
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Section 7
Current protection
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