7.4 BLOCKING INSTANTANEOUS PROTECTION FOR LOCKOUTS
Instantaneous protection can also be blocked for certain lockout conditions:
It is blocked when the CB maintenance lockout counter or excessiv
e fault frequency lockout has reached its
penultimate value.
For example, if the setting No. CB Ops Lock in the CB MONITOR SETUP column is set to 100 and the No. CB Ops
Maint = '99', the instantaneous protection can be blocked to ensure that the last CB trip before lockout will be due
to discriminative protection operation. This is controlled using the EFF Maint Lock setting (Excessive Fault
Frequency maintenance lockout). If this is set to Block Inst Prot, the instantaneous protection will be
blocked for the last CB Trip before lockout occurs.
Instantaneous protection can also be blocked when the IED is locked out, using the AR Lockout setting. It can also
be blocked after a manual close using the Manual Close setting. When the IED is in the Non-auto mode it can be
blocked by using the AR Deselected setting. The logic for these features is shown below.
P14x Chapter 13 - Autoreclose
P14xEd1-TM-EN-1 295
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