ABB REG670 Applications Manual page 432

Section 10
Voltage protection
426
U1
Ud>L1
U2
Ph L3
Ph L3
IEC06000390 V3 EN
Figure 210: Connection of voltage differential protection VDCPTOV function to
detect unbalance in capacitor banks (one phase only is shown)
VDCPTOV 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 U2). 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.
The application to supervise the voltage on two voltage transformers in the generator
circuit is shown in figure 211.
Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062
Single earthed wye
Ph L2
Ud>L1
U1 U2
Ph L3
Ph L2
1MRK 502 071-UEN -
Double wye
Ph L2
IEC06000390_1_en.vsd
Application manual