ABB Relion 670 Series Technical Reference Manual page 608

Section 11
Secondary system supervision
602
The function enable the internal signal FuseFailDetZeroSeq if the measured zero-
sequence voltage is higher than the set value 3V0PU and the measured zero-sequence
current is below the set value 3I0PU.
The function enable the internal signal FuseFailDetNegSeq if the measured negative
sequence voltage is higher than the set value 3V2PU and the measured negative
sequence current is below the set value 3I2PU.
A drop out delay of 100 ms for the measured zero-sequence and negative sequence
current will prevent a false fuse failure detection at un-equal breaker opening at the two
line ends.
Sequence Detection
3I0PU
IA
Zero
sequence
filter
IB
Negative
sequence
IC
filter
3I2PU
3V0PU
VA
Zero
sequence
filter
VB
Negative
sequence
VC
filter
3V2PU
ANSI10000036 V2 EN
Figure 303: Simplified logic diagram for sequence detection part
The calculated values 3V0, 3I0, 3I2 and 3V2 are available as service values on local
HMI and monitoring tool in PCM600.
Input and output signals
The output signals 3PH, BLKV and BLKZ can be blocked in the following conditions:
a
a>b 100 ms
b
0
AND
a
a>b 100 ms
b
0
AND
a
a>b
b
a
a>b
b
1MRK505222-UUS C
CurrZeroSeq
3I0
CurrNegSeq
3I2
FuseFailDetZeroSeq
FuseFailDetNegSeq
VoltZeroSeq
3V0
VoltNegSeq
3V2
ANSI10000036-2-en.vsd
Technical reference manual