![Arcteq AQ-F255 Instruction Manual Download Page 293](http://html1.mh-extra.com/html/arcteq/aq-f255/aq-f255_instruction-manual_2964952293.webp)
Table. 5.6.6. - 235. Measurement magnitudes used by the FLX function
Signals
Description
Time base
VT1 U1,U2,U3
L-N or L-L voltages of rst voltage transformer
5 ms
CT1 IL1,IL2,IL3
Measurement of phase L1/A, L2/B & L3/B current
5 ms
Fault locator triggering
Trig fault locator input de nes which signal triggers the fault locator. This can be any binary signal
generated by the unit. Generally using trip signal of protection functions or open status of the breaker is
used.
For the fault locator to trig and record distance there are there are several conditions that have to be
met. The rst thing when receiving a triggering signal function checks if the calculation is blocked.
Calculation blocking signals are determined by user set Block calculation matrix. Then the function
checks if phase to earth voltages are available. If phase-to-earth voltages are not available fault locator
can record only phase-to-phase impedance loops. If phase-to-earth voltages are available phase-to-
neutral impedance loops can be recorded as well. Depending on measured phase currents at the
moment of receiving a triggering signal the recorded impedance loop is chosen from the available
options. See the tables below.
Table. 5.6.6. - 236. Pick-up characteristics setting
Name
Description
Range
Step
Default
Trigger
current>
Affects to the decision which impedance loop is recorded or if
anything is recorded at all. See table below.
0.0xIn
0.1xIn
1xIn
Reactance
per km
Used to calculate the distance to fault
0.000…
5.000ohm/km
0.001ohm/km 0.125ohm/km
Table. 5.6.6. - 237. Current conditions needed to trig impedance recording.
Currents over limit
P-E voltages available
P-E Voltage not available
Recorded impedance
Recorded impedance
IL1,IL2,IL3
XL12
XL12
IL1,IL2
XL12
XL12
IL2,IL3
XL23
XL23
IL1,IL3
XL31
XL31
IL1
XL1
No trig
IL2
XL2
No trig
IL3
XL3
No trig
If none of the current measurement requirements are ful lled when the function receives a triggering
signal it will not record impedance.
Function blocking
In the blocking element the block signal is checked at the beginning of each program cycle. Blocking
signal is received from the blocking matrix for the function dedicated input. If blocking signal is active
when pick-up element activates the function shall not process the situation further.
From blocking of the function a HMI display event as well as time stamped blocking event with
information of the startup voltage values and fault type is issued.
AQ-F255
Instruction manual
Version: 2.00
© Arcteq Relays Ltd
292