ABB Relion 670 series, Technical Reference Manual

Page: 549 / 1232

VDCPTOV (60) function can be blocked from an external condition with the binary
BLOCK input. It can for example, be activated from Fuse failure supervision function
SDDRFUF.
To allow easy commissioning the measured differential voltage is available as service
value. This allows simple setting of the ratio correction factor to achieve full balance in
normal service.
The principle logic diagram is shown in figure 277 .
VDTrip_A
V1Low_A
AND
O
R
VDAlarm_A
VDTrip_B
VDAlarm_B
VDTrip_C
VDAlarm_C
AND
AND
AND
AND
AND
O
R
TRIP
PICKUP
ALARM
V1Low_B
V1Low_C
V2Low_A
V2Low_B
V2Low_C
AND
AND
0-tAlarm
OR
AND
AND
AND
BLOCK
AND
AND
V1LOW
V2LOW
en06000382_2_ansi.vsd
0
0-t1
0
0-tAlarm
0
0-tTrip
0 0-tReset
0
BlkDiffAtULow
AND
ANSI06000382 V3 EN
Figure 277: Principle logic for Voltage differential function VDCPTOV (60)
1MRK505222-UUS C
Section 8
Voltage protection
543
Technical reference manual