S&C Instruction Sheet 681-530
57
Overcurrent Control Settings
Table 13. IEEE Curves
Time Overcurrent Phase Protection
Inverse Segment
Standard Inverse (U1)
Very Inverse (U2)
Extremely Inverse
(U3)
Long-Time Inverse
(U4)
Short-Time Inverse
(U5)
Continuous Current
600
900/1200
Short Circuit, RMS Sym.
Short Circuit, RMS Sym.
12.5 and 16 kA
25 kA
12.5 and 16 kA
25 kA
Minimum Trip Current,
A
14 to 12500 in steps
of 0 .01
14 to 13200 in
steps of 0 .01
28 to 12500 in steps
of 0 .01
28 to 13200
in steps of
0 .01
Low-Current Cutoff, A
●
14 to 12500 in steps
of 0 .01
14 to 13200 in
steps of 0 .01
28 to 12500 in steps
of 0 .01
28 to 13200
in steps of
0 .01
Time Multiplier
0 .5 to 15 in steps of 0 .01
Time Adder, s
0 to 1000 in steps of 0 .01
Definite-Time Phase Protection Element #1
Definite-Time Current,
A
■
14 to 12500 in steps
of 0 .01
14 to 13200 in
steps of 0 .01
28 to 12500 in steps
of 0 .01
28 to 13200
in steps of
0 .01
Definite-Time Time, s
0 – 1000 in steps of 0 .001
Definite-Time Phase Protection Element #2
Definite-Time Current,
A
▲
14 to 12500 in steps
of 0 .01
14 to 13200 in
steps of 0 .01
28 to 12500 in steps
of 0 .01
28 to 13200
in steps of
0 .01
Definite-Time Time, s
◆
0 – 1000 in steps of 0 .001
Reset Time Parameters
Reset Type
TIMED
Reset Time, s
▼
0 to 1000 in steps of 0 .001
●
Low-current cutoff must be equal to or greater than the minimum trip current .
■
Definite time current must be greater than or equal to low-current cutoff and/or the minimum trip current .
▲
Definite Time Current 2 should be greater than or equal to Definite Time Current 1 .
◆
Time should be less than Definite-Time 1 .
▼
Accumulated value will reset to zero after Reset Time has elapsed .
