I.L. 40-201.9
Power Automation and Protection Division
I-6
REL 352 Version 1.00
Zone 2 (Z2G) should operate for all of the above faults.
For forward Zone 3 trips outside of Zone 2 trips, apply the following quantities. Check the apparent impedance
as well as the trip time. The trip time should be 1.0
±
5% seconds.
The following table tests external forward faults outside Zone 3 reach.
The system should not trip.
CG
Va = 69
∠
0
Vb = 69
∠
-120
Vc = 10
∠
+120
Ia = 0
Ib = 0
Ic = 4
∠
-135
1.5
∠
-105
V
I
Z app
AG
Va = 25
∠
0
Vb = 69
∠
-120
Vc = 69
∠
+120
Ia = 3
∠
-75
Ib = 0
Ic = 0
5.0
∠
75
BG
Va = 69
∠
0
Vb = 25
∠
-120
Vc = 69
∠
+120
Ia = 0
Ib = 3
∠
+165
Ic = 0
5.0
∠
75
CG
Va = 69
∠
0
Vb = 69
∠
-120
Vc = 25
∠
+120
Ia = 0
Ib = 0
Ic = 3
∠
+45
5.0
∠
75
V
I
AG
Va = 25
∠
0
Vb = 69
∠
-120
Vc = 69
∠
+120
Ia = 2
∠
-75
Ib = 0
Ic = 0
BG
Va = 69
∠
0
Vb = 25
∠
-120
Vc = 69
∠
+120
Ia = 0
Ib = 2
∠
+165
Ic = 0
CG
Va = 69
∠
0
Vb = 69
∠
-120
Vc = 25
∠
+120
Ia = 0
Ib = 0
Ic = 2
∠
+45
V
I
Z app