Application Examples; Auto-Reclose Function; Fast Tripping And Initiation Of Shot 1 Using Two; Protection Stages - ABB REF 610 Technical Reference Manual

1MRS 755535
5.
5.1.
5.1.1.
Feeder Protection Relay
Technical Reference Manual - ANSI Version

Application examples

Auto-reclose function

Fast tripping and initiation of shot 1 using two protection
elements
In several applications, such as fuse-saving applications involving down-stream
fuses, tripping and initiation of shot 1 should be fast (instantaneous or short-time
delayed) and of shot 2 and 3, and definite tripping time delayed.
In this example, two overcurrent elements are used, 51P and 50P-1. Element 50P-1
is given an instantaneous characteristic and element 51P a time delay. By setting
SG2/2 to 1 and SG2/7 to 1, element 50P-1 will be blocked by the AR function during
shot 2 and 3.
Trip
51P
Trip
50P-1
50P-1 Trip
Block 50P-1
CB Closed
CB Open
Shot 1
50P-1 TDLY
Fig. 5.1.1.-1 Fast initiation of shot 1 using one fast and one delayed element
In case of a short-circuit in the network, element 50P-1 will trip the circuit breaker
and initiate shot 1. At the time of shot initiation, the blocking of element 50P-1 will
be activated. If the network fault is not cleared, element 51P will trip the circuit
breaker and continue the auto-reclose sequence to shot 2, shot 3 and finally definite
tripping.
79
Block 50P-1 at
Shot 1,2 and 3
51P Trip 51P Trip
Block 50P-1
Shot 2
51P TDLY 51P TDLY
REF 610
Open CB
Close CB
Block 50P-1
SG2/2=1
SG2/7=1
51P Trip
Block 50P-1
Shot 3 Definite Trip
51P TDLY
Close CB
139