Negative Sequence Overcurrent Protection (“Neg Sequence O/C” Menu) - GE MiCOM P40 Agile Technical Manual

P44x/EN ST/Hb6
(ST) 4-24
Menu text
GROUP 1 – BACK-UP I>
time. The reference curve is based on Time Dial = 1.
Care: Certain manufacturer's use a mid-range value of time dial = 5 or 7. So; it may be
necessary to divide by 5 or 7 to achieve parity.
I>1 Reset Char
Setting to determine the type of reset / release characteristics of IEEE / US curves.
I>1 tRESET
Setting that determines the reset / release time reset characteristics (see section
P44x/EN AP).
I>2 Function
I>2 Direction
Sets the second phase overcurrent threshold (I>2) characteristics. The conditions are
'disabled', definite time (DT) or inverse definite minimum time (IDMT, see chapter
P44x/EN AP).
Settings are the same as for the first stage overcurrent element.
I>2 VTS Block
I>2 Current Set
I>2 Time delay
I>2 Time delay VTS
I>2 TMS
I>2 Time Dial
I>2 Reset Char
I>2 tRESET
I>3 Status
The third element is fixed as non-directional, for instantaneous or definite time delayed
tripping.
I>3 Current Set
I>3 Time delay
I>4 Status
The fourth element is only used for stub bus protection, where it is fixed as non-directional,
and only enabled when the opto input Stub Bus Isolator Open (Stub Bus Enable) is
energised. If the "stub bus enable" input is equal to 0, the I>4 function is still active, if the
"stub bus enable" input is equal to 1, only the I>4 function is active (not I>1, I>2 and I>3).
I>4 Current Set
I>4 Time Delay
I>4 should be used as a normal overcurrent stage if no stub bus condition is activated
through the binary input Stub Bus Enabled.
2.5 Negative sequence overcurrent protection ("NEG sequence O/C" menu)
When applying traditional phase overcurrent protection, the overcurrent elements must be
set higher than maximum load current, thereby limiting the element's sensitivity. Most
protection schemes also use an earth fault element operating from residual current, which
Default setting
DT DT or Inverse
0 0
DT Disabled, DT, IEC S Inverse, IEC V
Inverse, IEC E Inverse, UK LT Inverse,
IEEE M Inverse, IEEE V Inverse, IEEE E
Inverse, US Inverse, US ST Inverse
Non Directional Non-Directional, Directional Fwd,
Directional Rev
Non-Directional Block, Non-Directional
2.00 x In 0.08 x In
2 s 0 s
2 s 0 s
1 0.025
7 0.5
DT DT or Inverse
0 0 s
Enabled Disabled or Enabled
3 x In 0.08 x In
3 s 0 s
Disabled Disabled or Enabled
4 x In 0.08 x In
4 s 0 s
MiCOM P40 Agile P442, P444
Setting range
Min Max
100 s
10.00 x In
100 s
100 s
1.2
15
100 s
32 x In
100 s
32 x In
100 s
Setting
Step size
0.01 s
0.01 x In
0.01 s
0.01 s
0.005
0.1
0.01 s
0.01 x In
0.01 s
0.01 x In
0.01 s