Instruction manual
–
AQ F3x0 Feeder protection IED
15 (162
)
Figure 3-4 Phase-to-phase connection.
Ph-N Voltage:
Rated Primary U1-3: 20kV
Range: Type 100
Residual voltage:
Rated Primary U4: 11.54kV
(=20kv/
√
3)
The fourth input is reserved for zero sequence voltage or for a voltage from the other side
of the circuit breaker for synchron switching. Accordingly, the connected voltage must be
identified with parameter setting “Connection U4“. Here, phase
-to-neutral or phase-to-
phase voltage can be selected: Ph-N, Ph-Ph.
If needed, the phase voltages can be inverted by setting the parameter “Direction U1
-
3“.
This selection applies to each of the channels UL1, UL2 and UL3. The fourth voltage
channel can be inverted by setting the paramete
r “Direction U4“. This inversion may be
needed in protection functions such as distance protection or for any functions with
directional decision, or for checking the voltage vector positions.
These modified sampled values are available for further processing and for disturbance
recording.
The function block also provides parameters for setting the primary rated voltages of the
main voltage transformers. This function block does not need that parameter setting but
these values are passed on to function blocks such as displaying primary measured values,
primary power calculation, etc.
