Siemens SENTRON 3VL System Manual page 126

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