ABB REG670 - Logic Diagram

8.14.7.4 Logic diagram
IEC10000214-1-en.vsd
StartCurr
X
a
b
a>b
Voltage
control or
restraint
feature
Inverse
DEF time
selected
Inverse
time
selected
OR
STOC
TROC
MinPh-PhVoltage
MaxPhCurr
IEC10000214 V1 EN
Figure 210: Simplified internal logic diagram for overcurrent function
Operation_UV=On
StartVolt
AND
a
b
b>a
MinPh-phVoltage
BLKUV
IEC10000213-1-en.vsd
DEF time
selected
STUV
TRUV
IEC10000213 V1 EN
Figure 211: Simplified internal logic diagram for undervoltage function
8.14.7.5 Undervoltage protection
The undervoltage step simply compares the magnitude of the lowest measured phase-
phase voltage quantity with the set start level. The undervoltage step starts if the
magnitude of the measured voltage quantity is lower than the set level.
1MRK502052-UEN B Section 8
Current protection
451
Technical manual