ERL F-PRO 5100, User Manual

Page: 49 / 192

4 Protection Functions and Specifications
D02416R04.00 F-PRO 5100 User Manual 4-3
50N/51N/67 Neutral
Overcurrent
Neutral overcurrent provides protection for line-to-ground faults. You can de-
fine forward, reverse or non-directional control on either 50N or 51N func-
tions. All the curve definitions are the same as the phase overcurrent except
that this function uses 3I0 rather than phase current. The equation is:
For 3I0 > pickup For 3I0 < pickup
T 3 I 0
 
TMS A
B
3 I 0
IPickup
--------------------
 
 
p
1 –
--------------------------------------
+ = T 3 I 0
 
TMS
TR
3 IO
IPickup
--------------------
 
 
2
1 –
--------------------------------------
=
The Curve Type selection allows you to use a number of curves available in
this menu. All of these curve types are generated by the equation shown at the
bottom of the screen. If you choose a user-selectable curve, it can be created
using the parameters A, B and p.
The characteristic of the overcurrent function can be rescaled by clicking on
the characteristics using the right mouse key and by making a box around the
area of interest. The characteristic can be printed by pressing the Print Graph
option.
50N/51N Neutral Overcurrent
50N Enable/disable
Directional Forward, reverse, non-directional
Pickup 0.25 to 50.00 (5 A)
0.05 to 10.00 (1 A)
Pickup Delay 0.01 to 99.99 seconds
0.00 to 99.99 (non-directional)
51N Enable/disable
Directional Forward, reverse, non-directional
Pickup 0.25 to 50.00 (5 A)
0.05 to 10.00 (1 A)
Curve Type For details see “IEC and IEEE Curves” on page 4-1
TMS 0.01 to 10.00
A 0.0010 to 1000.0000
B 0.0000 to 10.0000
p 0.01 to 10.00
TR 0.10 to 100.00
Initiate Fault Location Enable/disable
ProLogic Control Enable/disable
46/50/51/67 Negative
Sequence
Overcurrent
Negative Sequence Overcurrent provides protection for any unbalanced faults.
Functions 46-50/46-51/67 are similar to 50N/51N/67 except they use negative