ERL L-PRO 4000, User Manual

Page: 91 / 406

4 Protection Functions and Specifications
D02706R02.30 L-PRO 4000 User Manual 4-41
46-50/46-51/67
Negative
Sequence
Overcurrent
Negative Sequence Overcurrent provides further backup protection for any un-
balanced faults. The user can define directional or non directionall control on
either 46-50 or 46-51 functions. All the curve definitions are the same as the
Phase Overcurrent. The only difference is that this function uses the negative
sequence current (I2) rather than phase current. The equation is:
Phase Setting Multiplier for Single Phase Open Pole Condition
50N Pickup Current Multiplier 0.10 to 2.00
50N Pickup Time Multiplier 0.10 to 2.00
51N Pickup Current Multiplier 0.10 to 2.00
51N Pickup Time Multiplier 0.10 to 2.00
Table 4.23: 50N/51N/67 Neutral Overcurrent Settings
For I
2
> pickup (9)
For I
2
> pickup
(10)
Table 4.24: 46-50/46-51N/67Negative Sequence Overcurrent Settings
46-50 Enable/Disable
Directional Directional, non-directional or combined
Pickup 0.50 to 50.00 (5 A)
0.10 to 10.00 (1 A)
Pickup Delay 0.00 to 99.99 seconds non-directional
0.01 to 99.99 seconds directional
46-51 Enable/Disable
Directional Directional, non-directional or combined
Pickup 0.50 to 50.00 (5 A)
0.10 to 10.00 (1 A)
Curve Type For details see Table 4.21: IEC and IEEE Curves on page
38.
TMS 0.01 to 10.00
T I 2
 
TMS B
A
I 2
Pickup
------------------
 
 
p
1 –
------------------------------------ + =
T I 2
 
TMS
TR
I 2
Pickup
------------------
 
 
2
1 –
----------------------------------- =