ABB RELION REX640 Technical Manual page 1043

1MRS759142 C
REX640
Technical Manual
Table 974: Detection of element failure location for internal fuse capacitor bank
Name of the phase angle
I_COM_ANGL_A
I_COM_ANGL_A
I_COM_ANGL_B
I_COM_ANGL_B
I_COM_ANGL_C
I_COM_ANGL_C
If external fuses are used, the direction of an unbalance current is opposite to that of
the bank where internal fuses are in use.
Table 975: Detection of element failure location for external fuse capacitor bank
Name of the phase angle
I_COM_ANGL_A
I_COM_ANGL_A
I_COM_ANGL_B
I_COM_ANGL_B
I_COM_ANGL_C
I_COM_ANGL_C
Level detector 1
The phasewise-compensated unbalance currents I_COM_AMPL_A,
I_COM_AMPL_B and I_COM_AMPL_C are compared to the set Start value. If the
compensated unbalance current in one or more phases exceeds the set Start value, the
Level detector 1 module sends the enabling signal to the Timer 1 module.
Timer 1
Once activated, the Timer 1 module 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
Phase angle of unbalance
current
0
~+180
0
~0
0
~+60
0
~–120
0
~–60
0
~+120
Phase angle of unbalance
current
0
~0
0
~+180
0
~–120
0
~+60
0
~+120
0
~–60
Section 4
Protection functions
Element failure branch location
(Figure 558)
Phase A - Branch 1 or Phase A -
Branch 4
Phase A - Branch 2 or Phase A -
Branch 3
Phase B - Branch 1 or Phase B -
Branch 4
Phase B - Branch 2 or Phase B -
Branch 3
Phase C - Branch 1 or Phase C -
Branch 4
Phase C - Branch 2 or Phase C -
Branch 3
Element failure branch location
(Figure 558)
Phase A - Branch 1 or Phase A -
Branch 4
Phase A - Branch 2 or Phase A -
Branch 3
Phase B - Branch 1 or Phase B -
Branch 4
Phase B - Branch 2 or Phase B -
Branch 3
Phase C - Branch 1 or Phase C -
Branch 4
Phase C - Branch 2 or Phase C -
Branch 3
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