ABB REC670 Applications Manual page 261

1MRK 511 401-UUS A
Bay control REC670 2.2 ANSI
Application manual
internal fuses instead of a current unbalance protection measuring the current
between the neutrals of two half's of the capacitor bank. The function requires
voltage transformers in all phases of the capacitor bank. Figure
different alternative connections of this function.
V1
Vd>L1
V2
Ph C
Ph C
ANSI06000390 V1 EN-US
Figure 97: Connection of voltage differential protection VDCPTOV (60) function to
detect unbalance in capacitor banks (one phase only is shown)
VDCPTOV (60) function has a block input (BLOCK) where a fuse failure supervision
(or MCB tripped) can be connected to prevent problems if one fuse in the capacitor
bank voltage transformer set has opened and not the other (capacitor voltage is
connected to input V2). It will also ensure that a fuse failure alarm is given instead of a
Undervoltage or Differential voltage alarm and/or tripping.
Fuse failure supervision (SDDRFUF) function for voltage transformers. In many
application the voltages of two fuse groups of the same voltage transformer or fuse
groups of two separate voltage transformers measuring the same voltage can be
supervised with this function. It will be an alternative for example, generator units
where often two voltage transformers are supplied for measurement and excitation
equipment.
Single grounded wye
Ph B
Vd>A
V1 V2
Ph C
Ph B
en06000390_ansi.vsd
Section 9
Voltage protection
97 shows some
Double wye
Ph B
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