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

Product Line
Sepam 80 Series

Resolution

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.

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.