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350 FEEDER PROTECTION SYSTEM – QUICKSTART GUIDE
ELECTRICAL INSTALLATION
CHAPTER 2: INSTALLATION
Figure 2-33: Ground/Sensitive Ground wiring
Zero sequence CT installation
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
SOURCE
898730A1.CDR
A
B
C
USED FOR POLARIZING
GROUND CURRENT INPUT
350
PHASE CURRENT
INPUTS
A
B
C
GROUND CURRENT INPUT
WITH ZERO SEQUENCE CT
GROUND CURRENT INPUT
WITH RESIDUAL CONNECTION
E8 D8
G
GROUND
I
N
N
I
G
E5
D5
D6
E6
D7
E7
G
I
N
GROUND
D8 E8
GROUND
D8
E8
Ground connection to neutral
must be on the source side
U
N
SHIELDED CABLE
LOAD
A
B
C
N
G
Ground
outside CT
Source
LOAD
SHIELDED CABLE
898733.CDR
A
B
C
Source
To ground;
must be on
load side
Stress cone
shields