21/07/2010
12
MRAR 01/96 C
5. Working Principles
5.1 Status Descriptions
For the illustration of the functional sequence the
MRAR
defines six conditions:
5.1.1 Inactive
The relay is in the inactive state when the following conditions are fulfilled:
•
The circuit breaker is in the OFF position
•
The unit is not in the blocked state
•
The unit is not in the "Starting/Cycle" state.
Activation of the unit due to protection faults is not possible in the inactive state, thus there can be no
automatic reclosing.
5.1.2 Reclaim Time
The relay is in the Reclaim Time State when the Reclaim Time:
•
Has not yet expired
•
Has not been interrupted by other faults
Activation of the unit due to protection faults is also not possible in the Reclaim Time State, thus no
auto reclosing can take place.
5.1.3 AR Ready
The relay is in the AR Ready State when the following conditions are met:
•
The Circuit Breaker is in the ON position
•
The Reclaim Time has expired
•
The unit is not in the blocked state
•
The unit is not in the "Starting/Cycle" state.
Only in the AR Ready State is any action due to protection faults able to take place.
5.1.4 AR Starting
In the AR Starting state the start conditions for automatic reclosing, by means of the protection
commands, and the circuit breaker are checked.
5.1.5 AR Cycle
The starting commands are carred out in the AR Cycle state and the results, AR Successful or AR
Unsuccessful, are evaluated accordingly.
