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I.L. 40-201.9
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.
I-6
V
CG
Va = 69 ∠0
Ia = 0
Vb = 69 ∠-120
Ib = 0
Vc = 10 ∠+120
Ic = 4∠-135
V
AG
Va = 25 ∠0
Ia = 3 ∠-75
Vb = 69 ∠-120
Ib = 0
Vc = 69 ∠+120
Ic = 0
BG
Va = 69 ∠0
Ia = 0
Vb = 25 ∠-120
Ib = 3∠+165
Vc = 69 ∠+120
Ic = 0
CG
Va = 69 ∠0
Ia = 0
Vb = 69 ∠-120
Ib = 0
Vc = 25 ∠+120
Ic = 3∠+45
V
AG
Va = 25 ∠0
Vb = 69 ∠-120
Vc = 69 ∠+120
BG
Va = 69 ∠0
Vb = 25 ∠-120
Vc = 69 ∠+120
CG
Va = 69 ∠0
Vb = 69 ∠-120
Vc = 25 ∠+120
Power Automation and Protection Division
I
Z app
1.5 ∠-105
I
Z app
5.0 ∠75
5.0 ∠75
5.0 ∠75
I
Ia = 2 ∠-75
Ib = 0
Ic = 0
Ia = 0
Ib = 2∠+165
Ic = 0
Ia = 0
Ib = 0
Ic = 2∠+45
REL 352 Version 1.00
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