CHAPTER 4: SETPOINTS
PROTECTION
845 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
4–179
Figure 4-60: Neutral Directional Overcurrent Protection logic diagram
FLEXLOGIC OPERAND
FLEXLOGIC OPERAND
SETTING
SETTING
SETTING
SETTING
SETTINGS
SETTING
SETTING
NEUTRAL
DIR OC
FUNCTION
:
NEUTRAL
DIR OC POL
VOL
T
:
NEUTRAL
DIR OC
POLARIZING
:
BLOCK
:
NEUTRAL
DIR OC FWD
LIMIT
ANGLE
:
NEUTRAL
DIR OC FWD
ECA
:
NEUTRAL
DIR OC REV
LIMIT
ANGLE
:
NEUTRAL
DIR OC FWD
PICKUP
:
NEUTRAL
DIR OC REV
PICKUP
:
NEUTRAL
DIR OC
POS-SEQ RESTRAINT
Ntrl Dir OC FWD
Ntrl Dir OC REV
Disabled
=
0
Measured VX
V
oltage
Calculated V
_0
}
}
Current
Ground Crt
(Ig
)
Zero Seq Crt
(I
_0)
Dual
NOTE
:
1)
CURRENT
POLARIZING IS POSSIBLE ONL
Y
IN RELA
YS WITH
THE GROUND CURRENT
INPUTS CONNECTED
T
O
AN
ADEQUA
TE CURRENT
POLARIZING SOURCE
2)
POSITIVE SEQUENCE RESTRAINT
IS NOT
APPLIED WHEN
I
_
1
IS BELOW
0.
8
x CT
Of
f=
0
Enabled
=
1
AND
AND
AND
AND
AND
AND
AND
OR
OR
OR
OR
Ig
0.
05xCT
3(
I_0
-
K I
_1)
PICKUP
3(
I_
0
-
K I_1
)
PICKUP
V
oltage Polarization
Current Polarization
-3V_0
3I
_0
FWD
FWD
FWD
REV
REV
REV
RUN
RUN
RUN
RUN
1.
25
cy
1
.5
cy
NEUTRAL
DIR OC POS
-
SEQ RESTRAINT
:
892716
A
2
.cdr
T
O NEUTRAL
T
OC
AND
IOC ELEMENTS
T
O NEUTRAL
T
OC
AND
IOC ELEMENTS
AND
SETPOINTS
SIGNAL
INPUT
:
CT Bank
1
-
J1
USED ONL
Y
IN
845
and
889
Summary of Contents for 845
Page 10: ...VIII 845 TRANSFORMER PROTECTION SYSTEM INSTRUCTION MANUAL ...
Page 219: ...CHAPTER 4 SETPOINTS SYSTEM 845 TRANSFORMER PROTECTION SYSTEM INSTRUCTION MANUAL 4 91 ...
Page 221: ...CHAPTER 4 SETPOINTS SYSTEM 845 TRANSFORMER PROTECTION SYSTEM INSTRUCTION MANUAL 4 93 ...
Page 222: ...4 94 845 TRANSFORMER PROTECTION SYSTEM INSTRUCTION MANUAL SYSTEM CHAPTER 4 SETPOINTS ...
Page 223: ...CHAPTER 4 SETPOINTS SYSTEM 845 TRANSFORMER PROTECTION SYSTEM INSTRUCTION MANUAL 4 95 ...
Page 224: ...4 96 845 TRANSFORMER PROTECTION SYSTEM INSTRUCTION MANUAL SYSTEM CHAPTER 4 SETPOINTS ...
Page 225: ...CHAPTER 4 SETPOINTS SYSTEM 845 TRANSFORMER PROTECTION SYSTEM INSTRUCTION MANUAL 4 97 ...
Page 226: ...4 98 845 TRANSFORMER PROTECTION SYSTEM INSTRUCTION MANUAL SYSTEM CHAPTER 4 SETPOINTS ...
Page 227: ...CHAPTER 4 SETPOINTS SYSTEM 845 TRANSFORMER PROTECTION SYSTEM INSTRUCTION MANUAL 4 99 ...
Page 396: ...4 268 845 TRANSFORMER PROTECTION SYSTEM INSTRUCTION MANUAL MONITORING CHAPTER 4 SETPOINTS ...
Page 526: ...6 22 845 TRANSFORMER PROTECTION SYSTEM INSTRUCTION MANUAL FLEXELEMENTS CHAPTER 6 METERING ...