Application Guide - NP900 Series
14 (504
)
Phase unbalance protection trips immediately when it
is activated.
Earth fault protection trips immediately when it is
activated.
incorrect.
Go to Measurement, Phasors and check the current
Phasors diagram.
When all is correctly connected the diagram should
look as below with symmetric feeding:
In following rows few most common cases are
presented
Phase polarity problems are easy to find since the vector diagram points out the opposite polarity in the wrongly
connected phase.
Phase L1 (A) polarity incorrect.
Measurements:
Phase currents
Sequence currents
IL1: 1.00 xIn / 0.00 deg
IL2: 1.00 xIn / 60.00 deg
IL3: 1.00 xIn / 300.00 deg
I1: 0.33 xIn / 180.00 deg
I2: 0.67 xIn / 0.00 deg
I0Calc: 0.67 xIn / 0.00 deg
Resolution:
-
Change wires to opposite in CT module connectors 1
– 2
-
Or from the Transformers, Phase CT scaling select
IL1 polarity to “Invert”.
Phase L2 (B) polarity incorrect.
Measurements:
Phase currents
Sequence currents
IL1: 1.00 xIn / 0.00 deg
IL2: 1.00 xIn / 60.00 deg
IL3: 1.00 xIn / 120.00 deg
I1: 0.33 xIn / 0.00 deg
I2: 0.67 xIn / -60.00 deg
I0Calc: 0.67 xIn / 60.00 deg
Resolution:
-
Change wires to opposite in CT module connectors 3
– 4
-
Or from the Transformers, Phase CT scaling select
IL2 polarity to “Invert”.
Phase L3 (C) polarity incorrect.
Measurements:
Phase currents
Sequence currents
IL1: 1.00 xIn / 0.00 deg
IL2: 1.00 xIn / 240.00 deg
IL3: 1.00 xIn / 300.00 deg
I1: 0.33 xIn / 0.00 deg
I2: 0.67 xIn / 60.00 deg
I0Calc: 0.67 xIn / -60.00 de
Resolution:
-
Change wires to opposite in CT module connectors 5
– 6
-
Or from the Transformers, Phase CT scaling select
IL3 polarity to “Invert”.
Содержание NP900 Series
Страница 1: ......
Страница 49: ...Application Guide NP900 Series 49 504 A996A Figure 3 2 1 3 25 Definite time operating characteristics...
Страница 50: ...Application Guide NP900 Series 50 504 A996A Figure 3 2 1 3 26 IEC predefined characteristics NI VI LTI and EI...
Страница 52: ...Application Guide NP900 Series 52 504 A996A Figure 3 2 1 3 28 IEEE predefined characteristics EI MI and VI...
Страница 243: ...Application Guide NP900 Series 243 504 A996A Figure 3 3 2 1 122 NPS biased thermal trip curves with kNPS values 7 and 10...
Страница 491: ...Application Guide NP900 Series 491 504 A996A 3 7 5 6 SETTING EXAMPLE...
Страница 504: ...Application Guide NP900 Series 504 504 A996A A996A...