Description
2.8 Electronic trip unit ETU
3VA27 molded case circuit breakers & 3WL10 air circuit breakers
78 Manual, 10/2018, L1V30499596002-01
Enhanced protection functions - only available with
MF Advanced metering function
Switchable short-time-delayed short-circuit
protection
(inverse-time in relation to I²t)
● ●
Setting range of delay time t
dsd
FW in forward
direction
0.1 to 0.5 s (in steps of 0.01)
0.1 to 0.5 s (in steps of 0.01)
Setting range of delay time t
dsd
BW in backward
direction
0.1 to 0.5 s (in steps of 0.01)
0.1 to 0.5 s (in steps of 0.01)
Switchover to alternative operating values with
directed (directional) short-circuit current during
the switch-on phase (inrush adaptation)
for tripping characteristic t=k (fixed) possible
● ●
Setting range of the switch-on phase 0.10 to 30 s (in steps of 0.01)
0.10 to 30 s (in steps of 0.01)
Setting range I
dsd
= I
n
x … during the switch-on
phase in the forward direction FW
0.6 to 10 (in steps of 0.1)
0.6 to 10 (in steps of 0.1)
Setting range I
dsd
= I
n
x … during the switch-on
phase in the backward direction BW
0.6 to 10 (in steps of 0.1)
0.6 to 10 (in steps of 0.1)
Settings DST phase difference angle 3.6°; 7.2°; 10.8°; 14.5°; 18.2°; 22.0°; 25.9°; 30°; 34.2°;
38.7°; 43.4°; 48.6°; 54.3°; 61.0°; 69.6°
Definition of direction of power flow Bottom → top; top → bottom
Default value: top → bottom
Phase voltage unbalance V-NBA
Protection function can be enabled/disabled ● ●
Setting range U
nba
phase voltage unbalance 2 to 90% (in steps of 1%)
2 to 90% (in steps of 1%)
Setting range of the delay time t
nba
for phase
voltage unbalance
0.50 to 60 s (in steps of 0.5)
0.50 to 60 s (in steps of 0.5)
Enabling/disabling of tripping on phase voltage
● ●
u
Undervoltage protection V
u
Protection function can be enabled/disabled
Setting range of undervoltage protection U
u
=
U
n
x ...
0.5 to 0.98 (in steps of 0.01)
0.5 to 0.98 (in steps of 0.01)
Setting range of the delay time for undervoltage
protection
0.05 to 120 s (in steps of
0.01)
0.05 to 120 s (in steps of
0.01)
Enabling/disabling of tripping on undervoltage
● ●
o
o
Protection function can be enabled/disabled
Setting range of overvoltage protection U
o
= U
n
x ...
1.02 to 1.5 (in steps of 0.01)
1.02 to 1.5 (in steps of 0.01)