Siemens 7SR10 Argus Series, Manual

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7SR10, 7SR11, 7SR12 Applications Guide
© 2018 Siemens Protection Devices Limited Chapter 7 Page 31 of 41
4.1.2 Auto-Reclose Example 2 (Use of Quicklogic with AR)
TIME
CURRENT
51-1
50-1
B A
I
1
I
2
Figure 4-2 Example of Logic Application
Requirement: The relay at location ‘A’ is required to provide a reclose sequence of 2 Instantaneous followed by 2
delayed recloses. Where the fault current level is between the values ‘I1’ and ‘I2’ and the first trip is initiated from
the 51-1 (IDMT) element, the IDMT characteristic should trip the CB and lockout the auto-reclose.
Typical settings are:
CONTROL & LOGIC > AUTORECLOSE PROT’N:
79 P/F Inst Trips : 50-1
79 P/F Delayed Trips : 51-1
CONTROL & LOGIC > AUTORECLOSE CONFIG > P/F SHOTS
79 P/F Prot’n Trip 1 : Inst
79 P/F Prot’n Trip 2 : Inst
79 P/F Prot’n Trip 3 : Delayed
79 P/F Prot’n Trip 4 : Delayed
The above settings are suitable at values of fault current above ‘I2’ however were a fault to occur with a current
value between ‘I1’ and ‘I2’ this would be detected by the 51-1 element only. As Prot’n Trip 1 = Inst then the relay
would trip and reclose whereas it is required to lockout for this occurrence.
To provide a lockout for the above faults an additional element 50-2 with identical settings to 50-1 is assigned as
a Delayed Trip and is used in conjunction with the Quick Logic feature i.e.
OUTPUT CONFIG>OUTPUT MATRIX: 51-1 = V1
OUTPUT CONFIG>OUTPUT MATRIX: 50-2 = V2
OUTPUT CONFIG>OUTPUT MATRIX: E1 = V3
CONTROL & LOGIC>QUICK LOGIC: E1 = V1.!V2
INPUT CONFIG>INPUT MATRIX: 79 Lockout = V3