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Indications
The Instruments Menu includes the following meters relevant to the status of the Auto-Reclose and Manual
Closing of the circuit breaker: -
Status of the AR sequence , AR Shot Count, CB Open Countdown Timer and CB Close Countdown
Timer
Inputs
External inputs to the AR functionality are wired to binary inputs. Functions which can be mapped to these binary
inputs include: -
79 In (edge triggered)
79 Out (level detected)
CB Closed
CB Open
79 Ext Trip
79 Ext Pickup
Outputs
Outputs are fully programmable to either binary outputs or LEDs. Programmable outputs include: -
79 Out Of Service
79 In Service
79 In Progress
79 AR Close CB
Manual Close CB
4.1.2
Auto Reclose sequences
The CONTROL & LOGIC>AUTO RECLOSE PROT'N and CONTROL & LOGIC>AUTORECLOSE CONFIG'
menus, allow the user to set independent Protection and Auto Reclose sequences for each type of fault i.e. Phase
Fault (P/F), Derived/Measured Earth Fault (E/F), Sensitive Earth Fault (SEF) or External Protections (EXTERN).
Each Auto Reclose sequence can be user set to up to four-shots i.e. five trips + four reclose sequence, with
independently configurable type of Protection Trip. Overcurrent and earth fault elements can be assigned to any
combination of Fast (Inst), Delayed or highset (HS) trips. Deadtime Delay time settings are independent for
each AR shot. The user has programming options for Auto Reclose Sequences up to the maximum shot count
i.e.:-
Inst or Delayed Trip 1 + (DeadTime 1: 0.1s-14400s)
+
Inst or Delayed Trip 2 + (DeadTime 2: 0.1s-14400s)
+
Inst or Delayed Trip 3 + (DeadTime 3: 0.1s-14400s)
+
Inst or Delayed Trip 4 + (DeadTime 4: 0.1s-14400s)
+
Inst or Delayed Trip 5 – Lockout.
The AR function recognizes developing faults and, as the shot count advances, automatically applies the correct
type of Protection and associated Dead time for that fault-type at that point in the sequence.
A typical sequence would consist of two Inst trips followed by at least one Delayed trip. This sequence enables
transient faults to be cleared quickly by the Inst trip(s) and permanent fault to be cleared by the combined
Delayed trip. The delayed trip must be 'graded' with other Recloser/CB's to ensure system discrimination is
maintained, ie.. that as much of the system as possible is live after the fault is cleared.
A HS trips to lockout setting is provided such that when the number of operations of elements assigned as HS
trips reach the setting the relay will go to lockout.
The number of Shots (Closes) is user programmable, note: - only one Shot Counter is used to advance the
sequence, the Controller selects the next Protection characteristic/Dead time according to the type of the last Trip
in the sequence e.g. PF, EF, SEF or EXTERNAL.
Reclose Dead Time
User programmable dead times are available for each protection trip operation.
©2012 Siemens Protection Devices Limited
7SR11 & 7SR12 Description Of Operation
79 Block Reclose
Block Close CB
Close CB
Open CB
79 Trip & Reclose
79 Trip & Lockout
79 Successful AR
79 Lockout
79 Close Onto Fault
79 Trip & Reclose
79 Trip & Lockout
79 Line Check
79 Reset Lockout
79 Lockout
Hot Line In
Hot Line Out
79 Block External
Successful Manual
Close
79 Last Trip Lockout
CB fail to close
Chapter 1 Page 53 of 76
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