Displays and operator controls
9.2 Overcurrent trip unit with LCD display
3VL molded-case circuit breakers
126 System Manual, 03/2009, 110 0110 - 02 DS 01
Characteristic
curve
Application View
/
6
,
*
ETU42 for line protection,LSIG/LSING function
Overload protection I
R
= 0.4 to 1 x I
n
Time-lag class t
R
= 2.5 to 30
Thermal memory selectable on/off
Short-circuit protection (short-time delay)
I
sd
= 1.5 to 10 x I
R
, t
sd
= 0 to 0.5 s
I
2
t selectable on/off
Short-circuit protection (instantaneous)
I
i
= 1.25 to 11 x I
n
(frame-size-dependent)
Ground fault protection:
Measuring method No. 1: (G
R
) vectorial
summation of the currents in the three phases
and neutral conductor (4-conductor systems);
I
Δn
= 0.4 to 1 x I
n
, versions "CL", "CM", "CN"
Measuring method No. 2: (G
GND
) direct
measurement of the ground-fault current using
a current converter, I
g
= 0.4 to 1 x I
n
, t
g
= 0.1
to 0.5 s; "CM" version
On 4-pole circuit breakers:
neutral conductor protection N: 50 to 100% I
R
selectable or adjustable.
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