4.22
SEL-751A Relay
Instruction Manual
Date Code 20100129
Protection and Logic Functions
Basic Protection
Figure 4.13
IEC Class A Curve (Standard Inverse): C1
0.60
0.05
0.50
0.40
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0.20
0.10
1.00
0.90
0.80
0.70
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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 (50Hz)
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 751A
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