Effective 8/2006
Page 10
I.L. 66A7534H04
Figure 2.2 Breaker Using Residual GF Sensing
In this scheme, all breaker secondary currents (at the 100 mA level) are summed together at the PC
board donut transformer to sense ground fault via element R5.
Do not jumper secondary contacts B-6, B-7. This will defeat the residual ground fault protection.
2
1
Notes:
Source
R5
Digitrip 520V
or 520MCV
1
K2-8
Load
K1-4
K1-3
10:1
10:1 AUX. CT
K2-9
K1-5
K1-2
Black
Trip
Actuator
+
-
L
B
L
C
L
A
K1-6
K1-7
K1-8
K1-9
CSA1
A-4
A-19
CSA2
A-5
CSB1
A-20
CSB2
A-6
CSC1
A-21
CSC2
X1
X2
B-5
B-4
R/1
R/1
CAUTION
IF THE PHASE CONNECTIONS ARE INCORRECT, A
NUISANCE TRIP MAY OCCUR. ALWAYS OBSERVE THE
POLARITY MARKINGS ON THE INSTALLATION DRAW-
INGS. TO INSURE CORRECT GROUND FAULT EQUIP-
MENT PERFORMANCE, CONDUCT FIELD TESTS TO
INSURE PROPER GROUND FAULT FUNCTIONALITY.
2.3.4 Ground Fault Settings
The adjustment of the ground fault functional settings
(FLAT response or I
2
t) is discussed in Section 4.8. The
effect of these settings is illustrated in the ground fault
time-current curve referenced in Section 9. The residual
ground fault pick-up settings are from 0.25x, 0.3x, 0.35x,
0.4x, 0.5x, 0.6x, 0.75x and OFF.
