Specifications

7SR242 Duobias Applications Guide

2.1.5.1 Example 1 – Further Analysis

Having established settings to ensure stability under load, transient and external fault conditions the following

considers the operating levels for internal faults. The ‘fault setting’ for internal fault conditions is affected by the

ICT Multiplier and ICT Connection settings applied:

W1 Internal Earth Fault

Figure 2-7: Relay Currents - Star Winding Internal Earth

Notes

A- E fault causes current to flow in the A and C elements

The Yd ICT connection reduces current flow by a factor of 1/3

Relay may indicate A and C faults