Ref1 + Ref2' Operation; Figure 3-7 Logic Diagram: 'Ref1 + Ref2' Protection - Siemens 7SR23 DAD Manual

Chapter 1) 7SR23 DAD Description Of Operation

3.4.3 'REF1 + REF2' Operation

The relay is configured for 'REF1 + REF2' operation using the SYSTEM CONFIG > Relay Config > REF1 +
REF2 setting.
When configured in this way the relay uses both 87REF elements. 87REF-1 earth current is measured by the
earth current input, 87REF-2 current is measured by the I current input. These elements operate independently
B
of each other.
For detailed information on the restricted earth fault functions refer to section 3.3.
Figure 3-7 Logic Diagram: 'REF1 + REF2' Protection
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