The measured current
amplitudes are OK but
the angles are strange./
The phase unbalance
protection trips
immediately after
activation./
The earth fault
protection trips
immediately after
activation.
The phase currents are connected to the measurement module but the order or polarity of one or
all phases is incorrect. In AQtivate, go to
Measurement
→
Phasors
and check the "Phase current
vectors" diagram. When all connections are correct, the diagram (symmetric feeding) should look
like this:
See the following tables for the most common problems with phase polarity and network rotation
(mixed phases).
The following table presents the most common problems with phase polarity. Problems with phase
polarity are easy to nd because the vector diagram points towards the opposite polarity when a phase
has been incorrectly connected.
Table. 5.2.1. - 5. Common phase polarity problems.
The polarity of Phase L1 (A) is incorrect.
Phase currents
IL1: 1.00 × In / 0.00 deg
IL2: 1.00 × In / 60.00 deg
IL3: 1.00 × In / 300.00 deg
Sequence currents
I1: 0.33 × In / 180.00 deg
I2: 0.67 × In / 0.00 deg
I0Calc: 0.67 × In / 0.00 deg
Solution options:
- switch the wires between the connectors 1 and 2 in the CT module
- invert the polarity of IL1 (
Measurement
→
Transformers
→
Phase CT scaling
)
The polarity of Phase L2 (B) is incorrect.
Phase currents
IL1: 1.00 × In / 0.00 deg
IL2: 1.00 × In / 60.00 deg
IL3: 1.00 × In / 120.00 deg
Sequence currents
I1: 0.33 × In / 0.00 deg
I2: 0.67 × In / -60.00 deg
I0Calc: 0.67 × In / 60.00 deg
Solution options:
- switch the wires between the connectors 3 and 4 in the CT module
- invert the polarity of IL2 (
Measurement
→
Transformers
→
Phase CT scaling
)
AQ-E215
Instruction manual
Version: 2.01
© Arcteq Relays Ltd
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