Signal
Description
Start L1
L1 phase pick-up signal
Start L2
L2 phase pick-up signal
Start L3
L3 phase pick-up signal
MeasFwd
Signals measurement in the forwards direction
MeasBwd
Signals measurement in the backwards direction
5.5.6
Configuration
GUID-B154716D-1084-4355-AAFC-CE606CA7C94E v1
The following parameters have to be set:
Base current
I
B
-Setting
Characteristic enabling current
IStart
Type of characteristic
c-Setting
Multiplier
k
1
-Setting
Characteristic angle
Angle
Time allowed for receipt of signal
t
Wait
Response at the end of the memorized power direction time
MemDirMode
Time during which the memorized direction is valid
MemDuration
Base current I
B
-Setting
A tripping current is not set on a directional overcurrent inverse function as it is on a definite
time overcurrent function. Instead the position of the characteristic is chosen such that it is
above the load current. The function, however, has a base current setting, which is set to the
full load current I
B1
of the protected unit. The base current setting determines the position of
the basic characteristic. The characteristic is enabled when the base current is exceeded by a
preset amount (
IStart). The adjustment of the base current I
B
to the load current I
B1
of the
protected unit instead of its rated current enables for:
•
IB1 < rated current of prot. unit: more sensitive protection
•
IB1 > rated current of prot. unit: maximum utilization of the thermal capability of the
protected unit
For example:
•
Load current of the protected unit I
B1
= 800 A
•
CT rated current I
N1
= 1000 A
•
I
N2
= 5 A
•
Protection rated current I
N
= 5 A
Protection base current:
Setting:
2
1
1
5
800
4
1000
N
B
B
N
I
A
I
I
A
A
I
A
4
0.8
5
B
N
I
A
I
A
1MRK 505 406-UEN B
Section 5
Bay protection functions
Bay protection functions REB500
107
Technical manual
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