Zero-Sequence Ct Installation - GE Multilin 850 Instruction Manual

CHAPTER 2: INSTALLATION

Zero-Sequence CT Installation

850 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
Figure 2-23: Restricted Ground Fault Inputs
The figure below shows the various CT connections and the exact placement of a Zero
Sequence current CT, so that ground fault current can be detected. Twisted pair cabling on
the Zero Sequence CT is recommended.
Figure 2-24: Zero Sequence (Core Balance) CT Installation
UNSHIELDED CABLE
Source
A B C N
LOAD
Ground connection to neutral
must be on the source side
G
Ground
outside CT
ELECTRICAL INSTALLATION
SHIELDED CABLE
Stress cone
Source
shields
A B C
To ground;
LOAD
must be on
load side
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