Setting Example For A Two-Ended Over-Head Transmission Line In A High Impedance Network - ABB REL650 Applications Manual

Section 3
REL650 setting examples
3.2
82
Pickup_N should be set lower than the smallest current to be detected by the most
sensitive step of the residual ovecurrent protection which is 100 A.
6. Set t1 to 0 s
Re-tip time delay: t1
7. Set t2 to 0.17 s
The delay time of the breaker failure protection BuTrip is chosen according to figure
32.
The maximum open time of the circuit breaker is considered to be 100 ms.
The BFP reset time is maximum 15 ms.
The margin should be chosen to about 2 cycles. This gives about 155 ms minimum
setting of back-up trip delay t2.
CCRBRF (50BF)
ANSI11000081 V1 EN
Figure 32: Time sequences for breaker failure protection setting
Setting example for a two-ended over-head
transmission line in a high impedance network
Setting calculations given for functions in the two-ended overhead
transmission line in a solidly grounded network are also valid for the two-
1MRK 506 334-UUS A
ANSI11000081_1_en.vsd
Application manual