I.B. 17555
Page 8
Effective 03/97
CURVE SHAPE
IT, I
2
T, I
4
T, FLAT, MOD, VERY, XTRM,
IECA, IECB, IECC, IECD
INVERSE TIME OVERCURRENT
0.100, 0.125, 0.150, 0.175, 0.200, 0.225,
+ 5%
PICKUP
0.250, 0.275, 0.300, 0.350, 0.400, 0.450,
0.500, 0.550, 0.600, 0.650, 0.700, 0.750,
0.800, 0.850, 0.900, 0.950, 1.00, 1.25,
1.50, 1.75, 2.00, NONE
INVERSE TIME OVERCURRENT
Curve = IT, I
2
T, I
4
T:
TIME MULTIPLIER
0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55,
+10%
➀ ➁ ➄
IT SC-5401-92B
0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, 0.95,
I
2
T SC-5400-92B
Ground Time Multiplier setting options
1.00, 1.25, 1.50, 1.75, 2.00, 2.25, 2.50, 2.75,
I
4
T SC-5399-92B
depend upon Ground Curve setting
3.00, 3.50, 4.00, 4.50, 5.00, 5.50, 6.00, 6.50,
selection.
7.00, 7.50, 8.00, 8.50, 9.00, 10.0, 12.5, 15.0,
17.5, 20.0, 22.5, 25.0, 27.5, 30.0, 35.0, 40.0
Curve = FLAT:
0.20, 0.25, 0.30, 0.35, 0.40, 0.45,0.50,
+ 0.05 SEC
FLAT
0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85,
SC-5402-92B
0.90, 0.95, 1.00, 1.25, 1.50, 1.75, 2.00
Curve = ANSI MOD, VERY, XTRM:
+10%
➀ ➂ ➄
MOD SC-6685-96
0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0,
VERY SC-6686-96
1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0,
XTRM SC-6687-96
2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0,
3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0,
4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0
Curve = IECA, IECB, IECC, IECD:
+10%
➀ ➂ ➃ ➄
IECA SC-6688-96
0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35,
IECB SC-6689-96
0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70,
IECC SC-6690-96
0.75, 0.80, 0.85, 0.90, 0.95, 1.00
IECD SC-6691-96
SHORT DELAY PICKUP
0.100, 0.125, 0.150, 0.175, 0.200, 0.225,
+ 10%
SC-5403-92B
0.250, 0.275, 0.300, 0.350, 0.400, 0.450,
0.500, 0.550, 0.600, 0.650, 0.700, 0.750,
0.800, 0.850, 0.900, 0.950, 1.00, 1.25,
1.50, 1.75, 2.00, 2.25, 2.50, 2.75, 3.00,
3.50, 4.00, 4.50, 5.00, 5.50, 6.00, 6.50,
7.00, 7.50, 8.00, 8.50, 9.00, 9.50, 10.0,
11.0, NONE
SHORT DELAY TIME
0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35,
+ 0.05 SEC
SC-5403-92B
(In Seconds)
0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70,
0.75, 0.80, 0.85, 0.90, 0.95, 1.00, 1.25,
1.50
INSTANTANEOUS PICKUP
0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80,
+ 10%
SC-5396-92B
0.85,0.90, 0.95, 1.00, 1.25, 1.50, 1.75,
2.00, 2.25, 2.50, 2.75, 3.00, 3.50, 4.00,
4.50, 5.00, 5.50, 6.00, 6.50, 7.00, 8.00,
8.50, 9.00, 9.50, 10.0, 11.0, NONE
Table 2.3 Characteristic for Ground Element
TYPE SETTING
AVAILABLE SETTINGS
TOLERANCE
CURVE #
NOTES:
➀
Curves go to constant operating time above 30 x I
n
.
➁
Tolerance: ± 10% or 0.09 seconds, whichever is larger. Minimum operating trip time is 0.05 seconds.
➂
Tolerance: ± 10% or 0.09 seconds, whichever is larger (>1.5 x I
pu
). Minimum trip time is 2 power line cycles.
➃
For IECD, the Time Multiplier Tolerance is ±0.05 seconds.
➄
For Ground Pickup
≤
0.2
pu
: trip time tolerance is ±15%.