Manual 37138C
ESDR 4T - Current Differential Protection Relay
Page 32/46
© Woodward
Modifying the Electrical Restraint
Stabilisation
Rush ON
Electrical restraint with inrush current
ON/OFF
ON
................As soon as the proportion of 2
nd
order harmonics exceeds the limit
configured in the parameter "Release value Rush", tripping of the dif-
ferential current 1 is restrained. The subsequent screens will be dis-
played.
OFF
..............No restraint occurs with the inrush current, and the subsequent
screens of this option are not displayed.
Release value
Rush 00%
Operating limit of electrical restraint with inrush current
10 to 50 %
The operating limit is a measure for the sensitivity of the electrical restraint. The
setting depends on the characteristics of the transformer being protected and the
network configuration.
Stabilisation
Overexcit. ON
Electrical restraint with over excitation
ON/OFF
ON
................As soon as the proportion of 5
th
order harmonics exceeds the limit
configured in the parameter "Release value Overexcit.", tripping of
the differential current 1 is restrained. The subsequent screens will be
displayed.
OFF
..............No restraint occurs with over excitation, and the subsequent screens
of this option are not displayed.
Release value
Overexcit. 00%
Operating limit of electrical restraint with over excitation
10 to 50 %
The operating limit is a measure for the sensitivity of the electrical restraint. The
setting depends on the characteristics of the transformer being protected and the
network configuration.
Rated frequency
00Hz
Rated frequency
50/60 Hz
Entering a value here specifies the rated frequency. The rated frequency is used to
calculate the harmonic vibrations.
Display
harmonics OFF
Display of harmonics
ON/OFF
ON
................The maximum values of the 2
nd
and 5
th
order harmonics are displayed
in the second line in display mode. The indicated values are always
plotted according to the highest value displayed and can be useful in
setting up. The values indicated are reset to zero by pressing the ac-
knowledgement button.
OFF
..............The proportion of harmonics is not displayed.
