ELECTRICAL INSTALLATION
Zero sequence CT installation
2–30
Figure 2-33: Ground/Sensitive Ground wiring
SOURCE
D8
E8
N
I
G
GROUND
GROUND CURRENT INPUT
USED FOR POLARIZING
The various CT connections and the exact placement of a Zero Sequence CT, for ground
fault current detection, are shown in the figure below. Twisted pair cabling on the Zero
Sequence CT is recommended.
Figure 2-34: Zero sequence core balance (CT) installation
U SHIELDED CABLE
Source
A
B
C
LOAD
A
E8
D8
I
N
G
GROUND
GROUND CURRENT INPUT
WITH ZERO SEQUENCE CT
Ground connection to neutral
must be on the source side
G
Ground
outside CT
350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 2: INSTALLATION
A
B
C
E5
E6
E7
350
B
C
PHASE CURRENT
INPUTS
D5
D6
D7
E8
D8
I
N
G
GROUND
GROUND CURRENT INPUT
WITH RESIDUAL CONNECTION
898730A1.CDR
SHIELDED CABLE
Stress cone
Source
A
B
C
LOAD
shields
To ground;
must be on
load side
898733.CDR