Eaton Cutler-Hammer Digitrip 3000, Instructions For Installation, Operation And Maintenance, Page: 67 / 92

I.B. 17555C
Effective November 1999
Page 61
7-2 DIGITRIP 3000 CURVE EQUATIONS
Thermal Curve Equation
ANSI/IEC Curve Equation
T = Trip Time
SLOPE M
D = Time Multiplier (0.2 to 40) IT 1
I = Input Current
I
2
T
2
M = Slope (0 = FLAT, 1 = IT, 2 = I
2
T, 4 = 1
4
T) I
4
T
4
K = 3 for phase, 1 for ground FLAT 0
Where:
I = Input Current
I
pu
= Pickup Current Setting
D = Time Multiplier Setting
P A B
ANSI MOD Moderately Inverse 0.02 0.0515 0.114
D = 0.1 - 5.0, step of 0.1
ANSI VERY Very Inverse 2 19.61 0.491
ANSI XTRM Extremely Inverse 2 28.2 0.1217
IEC-A Normal Inverse 0.02 0.14 0
D = 0.05 to 1.0
step of 0.05
IEC-B Very Inverse 1 13.5 0
IEC-C Extremely Inverse 2 80 0
IEC-D Definite Time 0 4