ABB RELION 620 Series Technical Manual page 450

Section 4
Protection functions
444
If this is not the case, the phase order may be wrong or the polarity of one current
transformer differs from the polarities of the other current transformers on the same side.
If the angle values I_ANGL_A1_B1, I_ANGL_B1_C1 and I_ANGL_C1_A1 show -120
degrees, the phase order is wrong on winding 1, for example, the high-voltage side. If the
angle values I_ANGL_A2_B2, I_ANGL_B2_C2 and I_ANGL_C2_A2 show -120
degrees, the phase order is wrong on winding 2, for example, the low-voltage side. If the
angle values I_ANGL_A3_B3, I_ANGL_B3_C3 and I_ANGL_C3_A3 show -120
degrees, the phase order is wrong on winding 3, for example, the tertiary side. If the angle
values I_ANGL_A1_B1, I_ANGL_B1_C1 and I_ANGL_C1_A1 do not show the same
value (+120 degrees), the polarity of one current transformer may be wrong. For example,
if the polarity of the current transformer measuring IL2 is wrong, the I_ANGL_A1_B1
show -60 degrees, I_ANGL_B1_C1 show -60 degrees and _ANGL_C1_A1 show +120
degrees.
When the phase order and the angle values are correct, the angle values I_ANGL_A1_A2,
I_ANGL_B1_B2 and I_ANGL_C1_C2 should show ±180 degrees and in case of three-
winding transformer, also the angle values I_ANGL_A1_A3, I_ANGL_B1_B3 and
I_ANGL_C1_C3 should show ±180 degrees. There can be several reasons if this is not the
case. If the angle values are 0, most probably the value given for CT connection 1-2 (or CT
connection 1-3) is wrong. If the angle values are something else, the value for Phase shift
Wnd 1-2 or Phase shift Wnd 1-3 can be wrong.
Table 340: Angle outputs when settings CT connection 1-2 and CT connection 1-3 match with the
actual CT connections on winding 1, 2 and 3
Angle output name
I_ANGL_A1_B1
I_ANGL_B1_C1
I_ANGL_C1_A1
I_ANGL_A2_B2
I_ANGL_B2_C2
I_ANGL_C2_A2
I_ANGL_A3_B3
I_ANGL_B3_C3
I_ANGL_C3_A3
I_ANGL_A1_A2
I_ANGL_B1_B2
I_ANGL_C1_C2
I_ANGL_A1_A3
I_ANGL_B1_B3
I_ANGL_C1_C3
Angle value Possible reason if not Ok
+120 Ok
+120 Ok
+120 Ok
+120 Ok
+120 Ok
+120 Ok
+120 Ok
+120 Ok
+120 Ok
±180 Ok
±180 Ok
±180 Ok
±180 Ok
±180 Ok
±180 Ok
1MAC504801-IB E
620 series ANSI
Technical Manual