SeqTypeIDir: This is used to select the type of operating current quantity i.e. Zero
seq or Neg seq for direction detection.
7.2.3.1 Common settings for all steps
M15282-81 v10
AngleRCA: Relay characteristic angle given in degree. This angle is defined as
shown in Figure
43. The angle is defined positive when the residual current lags
the reference voltage (Upol = 3U
0
or U
2
)
Upol = -3U
0
or
IN>Dir
RCA
Operation
-3U
2
IEC05000135-5-en.vsdx
IEC05000135 V5 EN-US
Figure 43: Relay characteristic angle given in degree
In a normal transmission network a normal value of RCA is about 65°. The setting
range is -180° to +180°.
polMethod: Defines if the directional polarization is from
• Voltage (3U
0
or U
2
)
• Current (3I
0
· ZNpol or 3I
2
·ZNpol where ZNpol is RNpol + jXNpol), or
• both currents and voltage, Dual (dual polarizing, (3U
0
+ 3I
0
· ZNpol) or (U
2
+
I
2
· ZNpol)).
Normally voltage polarizing from the internally calculated residual sum or an
external open delta is used.
Current polarizing is useful when the local source is strong and a high sensitivity is
required. In such cases the polarizing voltage (3U
0
) can be below 1% and it is then
necessary to use current polarizing or dual polarizing. Multiply the required set
current (primary) with the minimum impedance (ZNpol) and check that the
1MRK 505 388-UEN B Section 7
Current protection
Busbar protection REB650 2.2 IEC 105
Application manual
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