Siemens 7SR21 Manual page 52

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At the end of the 79 Reclose Blocked Delay due to presence of a persistent Block signal.
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When the 79 Elem HS Trips to Lockout count is reached.
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When the 79 Elem Delayed Trips to Lockout count is reached.
Once lockout has occurred, an alarm (79 Lockout) is issued and all further Close commands, except manual
close, are inhibited.
If the Lockout command is received while a Manual Close operation is in progress, the feature is immediately
locked-out.
Once the Lockout condition has been reached, it will be maintained until reset. The following will reset lockout:
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By a Manual Close command, from fascia, comms or Close CB binary input.
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By a 79 Reset Lockout binary input, provided there is no signal present that will cause Lockout.
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At the end of the 79 Minimum LO Delay time setting if 79 Reset LO by Timer is selected to
ENABLED, provided there is no signal present which will cause Lockout.
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Where Lockout was entered by an A/R Out signal during an Autoreclose sequence then a 79 In
signal must be received before Lockout can reset.
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By the CB Closed binary input, provided there is no signal present which will cause Lockout.
The Lockout condition has a delayed drop-off time of 2s. The Lockout condition can not be reset if there is an
active lockout input.
Note: If the 'CB Total Trip Count' or the 'CB Frequent Ops Count' target is reached the relay will do one delayed
tip and lockout.
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7SR21 & 7SR22 Argus Description of Operation
Chapter 1 Page 52 of 71