ERL F-PRO 116, User Manual

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5-10 F-PRO 116 User Manual D05125R01.20
46-50/51 Negative Sequence Overcurrent
Negative Sequence Overcurrent function provides protection for any unbalanced loading between
phases or to detect asymmetrical faults. Function 46-50 / 46-51 are similar to 50 / 51, except the
derived negative sequence current is utilized to drive the algorithm.
User can define the reset delay for the relay; It can be set as DTL or by ANSI delay. Setting of the
timer to a value other than zero, delays the resetting of the protection element timers for this
period. IDMTL equation, negative sequence current (I
2
) is used instead of I.
46 / 50 – Negative Sequence Overcurrent Logic diagram
Figure 5.9: Logic Diagram of 46/50 Function
Table 5.10: 46-50 Negative Sequence Overcurrent settings (No. of Stages – 1)
Setting Description Range
Function Activation Enable/disable
Pickup
0.05 to 0.95 (1 A) / 0.25 to 4.75 (5 A)
Pickup Delay
0.00 to 999.99
46 / 51
– IDMTL Negative Sequence Overcurrent Logic diagram
Figure 5.10: Logic Diagram of 46/51 Function
Pickup
Timer
Functional Block Via External Input
Function Enable
I2 Rms > I2 Pickup
46/50 Operated
Functional Block Via External Input
Function Enable
I2 Rms > I2 Pickup
46/51 Operated