Instruction manual
–
AQ F3x0 Feeder protection IED
118 (162
)
2.Dead Time Ph
10...100000 ms by
step of 10 ms
Dead time setting for the second reclosing cycle for line-to-line
fault. Default setting is 600 ms.
3.Dead Time Ph
10...100000 ms by
step of 10 ms
Dead time setting for the third reclosing cycle for line-to-line
fault. Default setting is 700 ms.
4.Dead Time Ph
10...100000 ms by
step of 10 ms
Dead time setting for the fourth reclosing cycle for line-to-line
fault. Default setting is 800 ms.
1.Dead Time Ef
0...100000 ms by
step of 10 ms
Dead time setting for the first reclosing cycle for earth fault.
Default setting is 1000 ms.
2.Dead Time Ef
10...100000 ms by
step of 10 ms
Dead time setting for the second reclosing cycle for earth fault.
Default setting is 2000 ms.
3.Dead Time Ef
10...100000 ms by
step of 10 ms
Dead time setting for the third reclosing cycle for earth fault.
Default setting is 3000 ms.
4.Dead Time Ef
10...100000 ms by
step of 10 ms
Dead time setting for the fourth reclosing cycle for earth fault.
Default setting is 4000 ms.
Accelerate 1. Trip
Enabled
Disabled
Acceleration of the 1
st
reclosing cycle trip command. Default
setting is Disabled.
Accelerate 2. Trip
Enabled
Disabled
Acceleration of the 2
nd
reclosing cycle trip command. Default
setting is Disabled.
Accelerate 3. Trip
Enabled
Disabled
Acceleration of the 3
rd
reclosing cycle trip command. Default
setting is Disabled.
Accelerate 4. Trip
Enabled
Disabled
Acceleration of the 4
th
reclosing cycle trip command. Default
setting is Disabled.
Accelerate final
Trip
Enabled
Disabled
Acceleration of the final trip command. Default setting is
Disabled.
3.3.8
S
WITCH ON TO FAULT LOGIC
Some protection functions, e.g. distance protection, directional overcurrent protection, etc.
need to decide the direction of the fault. This decision is based on the angle between the
voltage and the current. In case of close-in faults, however, the voltage of the faulty loop is
near zero: it is not sufficient for a directional decision. If there are no healthy phases, then
the voltage samples stored in the memory are applied to decide if the fault is forward or
reverse.
If the protected object is energized, the close command for the circuit breaker is received
in
“dead” condition. This means that the voltage samples
stored in the memory have zero
values. In this case the decision on the trip command is based on the programming of the
protection function for the “switch
-onto-
fault” condition.
This “switch
-onto-
fault” (SOTF) detection function prepares the
conditions for the
subsequent decision. The function can handle both automatic and manual close
commands.