ABB RELION 620 Series Technical Manual page 734

Section 9
Control functions
9.2.4.7
728
A070875-ANSI V1 EN
Figure 371: Configuration example of using the PROT_CRD output for protection
blocking
If the Protection crd limit setting has the value "1", the instantaneous three-phase
overcurrent protection function 50P-3 is disabled or blocked after the first shot.
Circuit breaker controller
Circuit breaker controller contains two features: SOTF and frequent-operation counter.
SOTF protects the AR function in permanent faults.
The circuit breaker position information is controlled with the CB closed Pos status
setting. The setting value "TRUE" means that when the circuit breaker is closed, the
CB_POS input is TRUE. When the setting value is "FALSE", the CB_POS input is
FALSE, provided that the circuit breaker is closed. The reclose command pulse time can
be controlled with the Close pulse time setting: the CLOSE_CB output is active for the
time set with the Close pulse time setting. The CLOSE_CB output is deactivated also when
the circuit breaker is detected to be closed, that is, when the CB_POS input changes from
open state to closed state. The Wait close time setting defines the time after the
CLOSE_CB command activation, during which the circuit breaker should be closed. If the
closing of circuit breaker does not happen during this time, the autoreclosing function is
driven to lockout or, if allowed, an auto-initiation is activated.
The main motivation for autoreclosing to begin with is the assumption that the fault is
temporary by nature, and that a momentary de-energizing of the power line and an
automatic reclosing restores the power supply. However, when the power line is manually
energized and an immediate protection trip is detected, it is very likely that the fault is of
a permanent type. An example of a permanent fault is, for example, energizing a power
line into a forgotten grounding after a maintenance work along the power line. In such
1MAC504801-IB E
620 series ANSI
Technical Manual