7SR210 & 7SR220 Applications Guide
Page 34 of 48 ©2018 Siemens Protection Devices Limited
4.1.2 Auto-Reclose Example 2 (Use of Quicklogic with AR)
TIME
Figure 4.1-2 Example of Logic Application
Requirement: The relay at location ‘A’ it 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
To Next Page
Loading...
