GE Industrial Solutions Entellisys 4.0 System User Manual - Manual (Page 90)

Single point functions 90
5
5.2.9.2 Accuracy
The location relay is dependant on the CT size and differential current between the pulsing
contactor’s on and off state. The minimum differential pulse current will, in turn, depend on fault
impedance and the size of the grounding resistors.
Table 5-8 CT accuracy in terms of detectable fault currents
CT Rating (Amps) Minimum detectable
differential current
(Differential amps)
150 1.0
400 1.0
800 1.0
1,600 1.0
2,000 1.2
3,200 1.5
4,000 2.0
5,000 3.0