MR ETOS ED - Motor Current Index (MCI)

9 Visualization
Maschinenfabrik Reinhausen GmbH 2020258 6385142/08 ENETOS
®
ED
The top diagram shows how often the on-load tap-changer was switched
into a particular tap position and how long it spent there. The bottom dia-
gram shows the time spent in the tap positions over the last 10 days.
Figure184: Tap-change operation statistics
► Go to Information > On-load tap-changer > Tap-change operation sta-
tistics.
9.25.4 Motor Current Index (MCI)
The term Motor Current Index (in accordance with IEEEPC57.143) de-
scribes the area below the curve of the motor current during an on-load tap-
change operation. The Motor Current Index is a measurement that takes into
account the inrush current, the present tap-change conditions and the tap-
change duration.
3
6
9
12
15
A
0
0 1 2 3 4s
I
t
200
400
600
800
1000
0
Tap-change operations
MCI
Motor current Motor Current Index
Figure185: Example illustration of the temporal progression of the motor current I and of the
Motor Current Index MCI calculated from this in comparison with the values of the MCI for fur-
ther on-load tap-change operations