ABB RED615 Technical Manual page 758

Section 9
Control functions
752
applications where two or more power transformers are connected to the same
busbar at the same time. The parallel operation modes of OLATCC are Master/
Follower (M/F), Minimizing Circulating Current (MCC) and Negative Reactance
Principle (NRP).
Configuration example for the Manual and Auto single modes
+
U12b
IL1b, IL2b, IL3b
GUID-88A1D370-2203-48CA-9843-76C309B4049D V4 EN
Figure 402: Basic connection diagram for the voltage regulator
Tap position indication (e.g. mA -signal)
M
-
+
LOWER
TCO
VT_
CT_
AUTO
-
Auto /
Lower
Manual
+
1YHT530004D05 D
+
TAP_POS
RAISE
IED
LOWER_LOCAL RAISE_LOCAL
-
Raise
+ +
Technical Manual
-
615 series