VAMP 265, Operation And Configuration Instructions

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Technical description 2 Protection functions 2.7 Earth fault protection I0>
(50N/51N)
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65
Inverse operation time (I
0
> stage only)
Inverse delay means that the operation time depends on the
amount the measured current exceeds the pick-up setting. The
bigger the fault current is the faster will be the operation.
Accomplished inverse delays are available for the I
0
> stage.
The inverse delay types are described in chapter 2.13. The
relay will show a scaleable graph of the configured delay on the
local panel display.
Inverse time limitation
The maximum measured secondary residual current is 10xI
0N
and maximum measured phase current is 50xI
N
. This limits the
scope of inverse curves with high pick-up settings. See chapter
2.13 for more information.
Setting groups
There are two settings groups available for each stage.
Switching between setting groups can be controlled by digital
inputs, virtual inputs (mimic display, communication, logic)
and manually.
Parameters of the undirectional earth fault stage
I
0
> (50N/51N)
Parameter Value Unit Description Note
Status -
Blocked
Start
Trip Current status of the stage
F
F
TripTime s Estimated time to trip
SCntr Cumulative start counter Clr
TCntr Cumulative trip counter Clr
SetGrp 1 or 2 Active setting group Set
SGrpDI
-
DIx
VIx
LEDx
VOx Digital signal to select the
active setting group
None
Digital input
Virtual input
LED indicator signal
Virtual output
Set
Force Off
On Force flag for status forcing for
test purposes. This is a
common flag for all stages and
output relays, too.
Automatically reset by a 5-
minute timeout. Set