The polarity of the polarizing quantity can be reversed by setting the
Pol reversal
to
"True", which turns the polarizing quantity by 180 degrees.
For definitions of different directional earth-fault characteristics, see
Chapter 4.2.2.8 Directional earth-fault characteristics
in this manual.
For definitions of different directional earth-fault characteristics, refer to
general function block features information.
The directional calculation module calculates several values which are presented in
the monitored data.
Table 338: Monitored data values
Monitored data values Description
FAULT_DIR The detected direction of fault during fault
situations, that is, when START output is ac-
tive.
DIRECTION The momentary operating direction indica-
tion output.
ANGLE Also called operating angle, shows the angle
difference between the polarizing quantity
(Uo, U
2
) and operating quantity (Io, I
2
).
ANGLE_RCA The angle difference between the operating
angle and Characteristic angle, that is, AN-
GLE_RCA = ANGLE – Characteristic angle.
I_OPER The current that is used for fault detection. If
the Operation mode setting is "Phase angle",
"Phase angle 80" or "Phase angle 88", I_OP-
ER is the measured or calculated residual cur-
rent. If the Operation mode setting is "IoSin",
I_OPER is calculated as follows I_OPER = Io x
sin(ANGLE). If the Operation mode setting is
"IoCos", I_OPER is calculated as follows I_OP-
ER = Io x cos(ANGLE).
Monitored data values are accessible on the LHMI or through tools via
communications.
Timer
Once activated, the timer activates the START output. Depending on the value of the
Operating curve type
setting, the time characteristics are according to DT or IDMT.
When the operation timer has reached the value of
Operate delay time
in the DT
mode or the maximum value defined by the inverse time curve, the OPERATE output
is activated.
When the user-programmable IDMT curve is selected, the operation time
characteristics are defined by the parameters
Curve parameter A
,
Curve parameter
B
,
Curve parameter C
,
Curve parameter D
and
Curve parameter E
.
If a drop-off situation happens, that is, a fault suddenly disappears before the
operate delay is exceeded, the timer reset state is activated. The functionality of
the timer in the reset state depends on the combination of the
Operating curve
Protection functions
1MRS758755 C
298 REC615 & RER615
Technical Manual
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