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5.105
Date Code 20171021
Instruction Manual
SEL-421 Relay
Protection Functions
Inverse-Time Overcurrent Elements
Figure 5.79
U.S. Very Inverse—U3
12.00
1.00
0.50
10.00
8.00
6.00
5.00
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15.00
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.5 .6 .7 .8 .9 1
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Time in Seconds
Multiples of Pickup
Time in Cycles 60 Hz (50 Hz)
3 (2.5)
6 (5)
15 (12.5)
30 (25)
60 (50)
600 (500)
150 (125)
300 (250)
1500 (1250)
3000 (2500)
6000 (5000)
Summary of Contents for SEL-421-4
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