Eaton Cutler-Hammer Digitrip 1150 Instructions Manual page 18

Page 18
Figure 2.8 Zero Sequence Sensing Scheme for Standard Circuit Breaker
Figure 2.9 Multiple Source/Multiple Ground Scheme
Courtesy of NationalSwitchgear.com
from cell (B-6,B-7) jumper disconnected, Residual Ground settings will apply.
φ
I /2
N
G
I /2
G
B5
i /2
g
B4
M1
i /2
G
R 5
B5
i /2 B4
g
R 5
Notes:
Breaker M2 trips since this is the only breaker seeing the I
No jumper on B-6, B-7 terminals - all breakers are programmed for standard Residual Ground Fault
protection.
AUX CTs not shown. Wiring needed at system level is shown as a dotted line.
Capital letters represent primary current. Lowercase letters represent secondary current.
The three breakers (M1, M2, and T) must all have the same breaker/sensor rating.
1
2
3
4
If the breaker is removed
φ
I /2
N
G
I /2
G
i /2
i
g
g
B5
I
G
i /2
g
B4
M2
T
R 5
Neutral Sensors Wired
in a Loop Configuration
I
G
fault via element R .
G 5
I.L. 70C1036H05
Internal
Digitrip
Sensor
i
g
Effective 10/2004