Manual MRG3
SEG Electronics GmbH
DOK-TD-MRG3, Rev. D
69
6.6 Example of a test circuit for MRG3-IER-relay with earth
current directional feature
Figure 6.4: Test circuit for the testing of the earth directional element
For testing relay MRG3-IER with earth current directional feature, current and voltage source sup-
plies with adjustable phase shifting are required. The phase position of the respective power
source should be adjust-able.
Figure 6.4 shows an example of a single phase test circuit with adjustable voltage and current test-
ing a re-lay with directional feature, one of the input voltage (terminals B1
– A2) shall be applied to
the relay with a constant value within its effective range. The other input current (terminals B1
– B2)
and phase angle shall be appropriately varied.
With the aid of phase angle indicated on the display the correct function of the relay MRG3-IER can
be checked.
Parameters I
E>
and I
E>>
should be set to EXIT.
The following measured values are shown:
Measured value
related LED
earth current
E
active share
E + E
P
reactive share
E + E
Q
earth voltage
U + E
angle
U + E