VAMP Ltd
Overcurrent and earth-fault relay
Technical Description
VAMP 130
VM130.EN003
Vamp 24h support phone : +358 (0)40 573 6316
13
2.2.2.
Non-directional earth-fault protection
(50/51N)
The earth-fault unit of the combined overcurrent and earth-
fault relay VAMP 130 is provided with two energizing inputs
rated 5 A and 1 A, software selection.
The earth-fault unit measures the fundamental frequency
component Io. In the VAMP 130 relay this means that the
degree of attenuation of the third harmonic is at least 60 dB,
which contributes to the extremely high accuracy of the earth-
fault protection.
Figure 2.2.2-1 Block diagram of the earth-fault stage I
0
>.
Figure 2.2.2-2 Block diagram of the earth-fault stage I
0
>>.
