SEG Electronics GmbH
Manual MRG3
14
DOK-TD-MRG3, Rev. D
3.1.8 Code plugs
The measuring range of phase and residual voltage can be adjusted via code plugs. For the meas-
uring range from 0
– 150 V, the code plugs have to be adjusted to X-100V; for the measuring range
0
– 600 V, adjust the code plugs to x_400V. the x, in this case, is used as a replacement character
for the phases L1, L2, L3 and U_E.
Encoding:
100V L1: Measuring range 0 -150V in phase U_L1
L2 100V: Measuring range 0 -150V in phase U_L2
100V L3: Measuring range 0 -150V in phase U_L3
100V U_E: Measuring range 0 -150V in phase U0
L1 400V: Measuring range 0 - 60V in phase U_L1
400V L2: Measuring range 0 - 600V in phase U_L2
L3 400V: Measuring range 0 . 600V in phase U_L3
U_E 400V: Measuring range 0 - 600V in phase U0
Based on the set value of the secondary transformers’ rated voltage, a change-over to the measur-
ing range is automatically detected by the MRG3 (refer to chapter 5.3.3). This set value determines
the secondary rated voltage of the device. If the adjusted value is lower than 138V, the MRG3 relay
recognizes the measuring range 0
– 150V; at a value of 138V and up, measuring range 0 – 600V
will be detected.
Attention:
Factory setting of the coding plugs is 400V. To avoid damage of the relay, the proper measuring
range must always be observed. The measuring range is to be set for each phase separately.
Figure 3.8: Change-over to/of measuring range for residual voltage UO