Protection Options For The Check Zone - GE P741 Technical Manual

Operation
MiCOM P741, P742, P743
1.2.8.2

Protection options for the Check Zone

1.2.8.2.1 Options for a Circuitry Fault
There are 5 options:
1. Blocking Latched
An alarm is provided and this alarm can only be reset manually,
The Check Zone is blocked and this blocking can only be reset manually.
2. Alarm Latched
An alarm is provided and this alarm can only be reset manually,
The Check Zone is blocked and this blocking will be automatically reset once the
differential current will disappear and after the set reset timer.
3. Self-Reset
An alarm is provided and this alarm can only be reset manually,
The Check Zone is blocked and this blocking will be automatically reset once the
differential current will disappear and after the set reset timer.
These 3 options avoid operation of the other zones in case of internal fault during a circuitry
fault in the Check Zone.
4. Alarm and No blocking
An alarm is provided and this alarm can only be reset manually,
The Check Zone is not blocked
5. Alarm Self-Reset and No blocking
An alarm is provided.
The Check Zone is not blocked
These 2 options allow operation of the other zones in case of internal fault during a circuitry
fault in the Check Zone.
1.2.8.2.2 Options for a PU error mode
There are 5 options:
1. Blocking Latched
An alarm is provided and this alarm can only be reset manually,
The zone is blocked and this blocking can only be reset manually.
2. Alarm Latched
An alarm is provided and this alarm can only be reset manually,
The Check Zone is blocked and this blocking will be automatically reset once the
communication will be reinstated and after the set reset timer.
3. Self-Reset
An alarm is provided and the Check Zone is blocked.
The alarm and the blocking will be automatically reset once the communication will be
reinstated and after the set reset timer.
These 3 options block the operation of the other zones in case of loss of the Check Zone.
4. Alarm and No blocking
An alarm is provided and this alarm can only be reset manually,
The Check Zone is not blocked
5. Alarm Self-Reset and No blocking
An alarm is provided.
The Check Zone is not blocked
These 2 options allow the operation of the other zones in case of loss of the Check Zone.
P74x/EN OP/Na7
(OP) 5-13
OP