Siemens Sentron 3VA - Page 132

Applications
3.1 Use of the 3VA UL molded case circuit breakers in line protection
3VA molded case circuit breakers with UL and IEC certification
130 Manual, 01/2019, L1V30435333-01
Short-time delayed short circuit protection S:
•
I
sd
Adjustable from 0.6 to 9 / 10 x I
n
I
sd
= 40 A: In steps of 0.5 A
I
sd
≥ 100 A: In steps of 1 A
•
t
sd
Adjustable from 0.05 to 0.5 s
with a reference point of I
sd
= 8 x I
r
in steps of 0.01 s
The curve shape I
2
t = constant can be deactivated.
Instantaneous short-circuit protection I:
•
I
i
Adjustable from 1.5 to 9 / 10 / 12 x I
n
(dependent on rated operational current
and frame size)
In steps of 1 A
Ground-fault protection G:
The detection of the ground-fault current is based on a vectorial summation of the phase
currents and the neutral conductor current for 4-pole or 3-pole circuit breakers with external
current transformer for N conductor.
•
I
g
Adjustable from 0.2 / 0.4 to 1.0 x I
n
In steps of 1 A
•
t
g
Adjustable from 0.05 to 0.8 s
with a reference point of 2 x I
g
In steps of 0.01 s
•
Changeover of measurement method from "rES" (measurement method 1) to "d Ir"
(measurement method 2), for details see chapter Ground-fault protection (Page 70)
An alarm threshold I
gA
between 0.2 to 1 x I
n
can also be set. In steps of 1 A
The current-dependent curve shape I
2
t = constant can be deactivated.
Ground-fault protection G can
not
be deactivated.