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How to wire Current Transformers (CT) on Sepam Series 80 relay for differential protection (ANSI 87)

Goals and Symptoms

This document explains how to wire CTs for differential protection (ANSI 87) on the Sepam Series 80 relay and what type of current values it generates.

Causes and Fixes

Wiring Current CTs for Differential Protection (ANSI 87)

Feeder

  

For feeder applications:

    • CTs located on primary side of transformer or motor are wired to B1 using a CCA634 connector and produce a Ia, Ib & Ic current.
    • CTs located on secondary side of transformer or motor are wired to B2 using a CCA634 connector and produce a I'a, I'b & I'c current.
Main

For Main applications:

    • CTs located on primary side of transformer or generator are wired to B2 using a CCA634 connector and produce a I'a, I'b & I'c current.
    • CTs located on secondary side of transformer or generator are wired to B1 using a CCA634 connector and produce a Ia, Ib & Ic current.

 


AEDL3

 

  • Date Created: February 22, 2008
    Last Revised: March 25, 2008
    Public
    Original Author: JJ
    All content © 1992-2008 Schneider Electric

Legacy KB System (APS) Data: RESL191502 V1.0, Originally authored by PhHa on 03/25/2008, Last Edited by PhHa on 03/25/2008
Related ranges: Sepam series 80
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