ABB rec670 - Page 140

ANSI05000427-2-en.vsd
I>
R
Rres
Rl
Rct
Rct
Rl
VR
a) Through load situation
b) Through fault situation
VR
VR
c) Internal faults
VR
Protected Object
ANSI05000427 V2 EN-US
Figure 49: The high impedance principle for one phase with two current
transformer inputs
Section 7 1MRK 511 401-UUS A
Differential protection
134 Bay control REC670 2.2 ANSI
Application manual