/PERATING INSTRUCTIONS
3*
6
# ' #
#4 %22 )M
!
3ECONDARY CURRENT ABOVE WHICH THE ANGLE ERROR IS
PRACTICALLY CONSTANT
3MALLEST SETTING VALUE
!
,ARGEST SETTING VALUE
!
m
n
#4 %22 &
%RROR ANGLE OF CURRENT TRANSFORMER AT )
3MALLEST SETTING VALUE
DEG
,ARGEST SETTING VALUE
DEG
m
n
4HE FUNCTION EARTH FAULT DETECTION COMPRISES RESID
UAL VOLTAGE DETECTION DETERMINATION OF THE EARTH
FAULTED PHASE USING THE MAGNITUDE OF THE PHASE
TO EARTH VOLTAGES AND DIRECTION DISCRIMINATION
WHICH
LATTER
IS
POSSIBLE
ONLY
IN
MODEL
3*
J JJJJ
OR
4HE RESIDUAL VOLTAGE 5
%
INITIATES EARTH FAULT DETEC
TION )T IS SET IN ADDRESSES OR AND RELEASES
THE DIRECTION DETERMINATION )F THE VOLTAGE INPUTS OF
THE RELAY ARE CONNECTED TO THREE STAR CONNECTED
VOLTAGE TRANSFORMERS THE RESIDUAL VOLTAGE IS CALCU
LATED FROM THE THREE PHASE TO EARTH VOLTAGES SUCH
THAT IT CORRESPONDS TO THE RATED VOLTAGE AT FULL DIS
PLACEMENT OF THE VOLTAGE TRIANGLE 4HE FOLLOWING IS
VALID
5
%
5
,
5
,
5
,
o
o
|
5
)F THE VOLTAGE INPUTS OF THE RELAY ARE CONNECTED TO TWO
PHASE EARTH CONNECTED VOLTAGE TRANSFORMERS
5
, %
5
, %
AND THE DISPLACEMENT VOLTAGE 5
%.
THEN THE DISPLACEMENT VOLTAGE IS IMMEDIATELY MEA
SURED 4HE MISSING VOLTAGE 5
, %
IS THEN CALCULATED
4HE PICK UP VALUE 5
%
IN ADDRESS CORRESPONDS
TO THIS VOLTAGE WHEREBY A HIGHER SENSITIVITY IS ALLOWED
WHEN THE DISPLACEMENT VOLTAGE IS DIRECTLY CON
NECTED $EPENDENT ON THE CONFIGURATION UNDER AD
DRESS EITHER ADDRESS FOR DIRECT CONNEC
TION OR ADDRESS FOR CALCULATED DISPLACEMENT
VOLTAGE IS AVAILABLE
3INCE FOR EARTH FAULTS IN
ISOLATED
OR
COMPENSATED
NETWORKS THE FULL DISPLACEMENT VOLTAGE APPEARS THE
SETTING VALUE IS NOT CRITICAL IT SHOULD LIE BETWEEN 6
AN 6 %ARTH FAULT IS DETECTED AND ANNUNCIATED ONLY
WHEN THE DISPLACEMENT VOLTAGE HAS BEEN STAYED FOR
THE DURATION 4 %& ADDRESS )N
EARTHED
NET
WORKS THE SET VALUE OF THE EARTH VOLTAGE 5E CAN BE
MORE SENSITIVE SMALLER BUT IT SHALL NOT BE EXCEEDED
BY OPERATIONAL ASYMMETRY OF THE VOLTAGES OF THE
POWER SYSTEM
&OR PHASE DETERMINATION 5PH ADDRESS IS
THE CRITERION FOR THE EARTH FAULTED PHASE WHEN SI
MULTANEOUSLY THE OTHER TWO PHASE VOLTAGES HAVE EX
CEEDED 5PH ADDRESS !CCORDINGLY 5PH
MUST BE SET LOWER THAN THE MINIMUM OPERATIONAL
PHASE EARTH VOLTAGE 4HIS SETTING IS HOWEVER ALSO
NOT CRITICAL 6 FACTORY SETTING SHOULD ALWAYS BE
ADEQUATE 5PH MUST LIE ABOVE THE MAXIMUM OP
ERATIONAL PHASE EARTH VOLTAGE BUT BELOW THE MINI
MUM OPERATIONAL PHASE PHASE VOLTAGE THEREFORE
FOR EXAMPLE 6 AT 5
.
6 4HESE PARAMETERS
ARE
IRRELEVANT IN EARTHED
SYSTEMS
0ICK UP BY THE DISPLACEMENT VOLTAGE CAN BE USED
FOR TIME DELAYED TRIP COMMAND 0RE CONDITION IS
THAT THE %!24( &!5,4 DETECTION IS SWITCHED
/.
IN
ADDRESS FURTHER % &,4 $%4 7)4( 5% /2 )%%
MUST BE CONFIGURED UNDER ADDRESS 4RIP DELAY
IS THEN SET UNDER ADDRESS 4 5% .OTE THAT THE
TOTAL COMMAND TIME IS COMPOSED OF THE INHERENT
MEASURING TIME APPROXIMATELY MS PLUS PICK
UP DELAY 4 %& ADDRESS PLUS TRIP DELAY 4
5% ADDRESS
0HASE EARTH VOLTAGE OF A FAULTED PHASE WHICH WILL BE
SAFELY UNDERSHOT UNDER EARTH FAULT CONDITIONS
3MALLEST SETTING VALUE
,ARGEST SETTING VALUE
6
6
5PH
6
m
n
ONLY FOR MODEL 3*
J JJJJ
JJJJ
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