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VAMP Ltd
Feeder and motor manager
Technical description
VAMP 257
VM257.EN002
VAMP 24h support phone : +358 (0)20 753 3264
25
Setting parameters of earth-fault location:
EFDi
Parameter Value
Unit
Default Description
EFMode
Normal;
Reverse
- Normal
Normal: The resistor
is switched ON
during a fault.
Reverse: The resistor
is switched OFF
during a fault
TrigIn Io;I2;DI1
-
Io Triggering
input:
Io: earth fault
current will trig the
function.
I
2
: negative phase
sequence current will
trig the function
DI1: the function is
triggered by
activating the digital
input 1
UoTrig
1 … 80
% Uon
20
Trig level for Uo
Itrig
10 … 800
% In
80
Trig level for current
Event
On: Off
-
On
Event mask
Measured and recorded values of earth-fault location:
EFDi
Parameter Value Unit Description
Fault ph
Fault phase information
X
ohm
Fault
reactance
Date -
Fault
date
Time -
Fault
time
Time ms
Fault
time
Measured
values/
recorded
values
Count
-
Number
of
faults
2.3.4.
Directional overcurrent protection (67)
The three-phase directional overcurrent function consists of
four separately adjustable stages, stage I
dir
>, stage I
dir
>>, stage
I
dir
>>> and stage I
dir
>>>>.
These directional overcurrent stages can be used for directional
short circuit protection. The stages have two modes: directional
and non-directional. The bi-directional operation is possible by
setting the both stages in a directional mode and setting the
base angle to have a 180
°
difference.
The direction is based on the phase angle of the power phasor.
The power phasor is calculated from the base frequency
components of the measured phase currents and line voltages,
taking into account the 30
°
phase/main angle.
The base angle is configurable. For a short circuit with power
factor 0.707 (the resistive and inductive components of the fault