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1.2.1.3
Input Transformer (I P ) Check
Step 6.
30 ∠0°
V
=
A
70 ∠-120°
V
=
B
70 ∠120°
V
=
C
Apply forward fault current I
4A ± 5%. The display should show "Z1G AG".
Repeat for B and C phases per the following table:
Phase B
70 ∠120°
V
=
A
30 ∠0°
V
=
B
70 ∠-120°
V
=
C
4 ∠-75°
I
=
B
Change the settings from Table A-1as follows:
ZIP
=
OUT
ZIG
=
OUT
DIRU
=
DUAL
GBCV
=
CO-8
GBPU
=
0.5
GDIR
=
YES
GTC
=
24
For a dual polarizing ground directional unit (DIRU = DUAL) test, connect the test
circuit shown in Figure B-4 (page B-9). Apply I
and 11(-), and apply a balanced 3-phase voltage (70 Vac) to Va, Vb, Vc, and Vn.
Apply Ia = 4A to terminals 6 (+) and 5 (-). The relay should trip at the following an-
gles:
• -3°
• -90° (± 87°)
• -177°
The relay should not trip at the following angles:
• +3°
• +90° (± 87°)
• +177°
Change the settings back to those of Table A-1 (page A-27).
∠-75° suddenly. The relay should trip for I
A
Phase C
70 ∠-120°
V
=
A
70 ∠120°
V
=
B
30 ∠0°
V
=
C
4 ∠-75°
I
=
C
= 1.0A ∠−90° to terminals 12(+)
P
I.L. 40-385.7
=
A
A-23
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