Eaton Digitrip 3000 series - Page 53

DT3000 Instruction Leaflet
I.B. 17555D Effective: Date 07/02 Page 49
For more information visit: www.cutler-hammer.eaton.com
Supersedes I.B. 17555C dated November 1999
Figure 7-8 Inverse Time Overcurrent Ground I
4
T Curve (SC-5399-92B)
0.01
0.10
1.00
10.00
100.00
1000.00
10000.00
0.1 1 10 100
Multiple of In (I/I
n
)
Trip Time (seconds)
0.2 Seconds at 1 per Unit
Minimum Pickup 0.1 Maximum Pickup 2.0
Adjustable Inverse Time Overcurrent Ground Pickup
(x I
n
) (0.1……….2.0 None)
Adjustable Inverse Time Overcurrent Time Multiplier Ground
(Sec. @ 1 x I
n
) (0.2 s……….40 s)
Tolerance: Inverse Time Overcurrent Pickup is ±5%
Inverse Time Overcurrent Time Multiplier is ±10 or ±0.9 s
whichever is larger
Minimum Trip Time is 0.05 s
Note: Pickup of 0.2 x with Inverse Time Overcurrent Time of
40 s @ 1 x makes T > 10000 s
40 Seconds at 1 per Unit
5 Seconds at 1 per Unit