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
116
Manual, 01/2019, L1V30435333-01
Overload protection L:
•
I
r
Adjustable in 10 steps from 0.4 to 1.0 x I
n
:
0.4 / 0.5 / 0.6 / 0.7 / 0.75 / 0.8 / 0.85 / 0.9 / 0.95 / 1.0
•
t
ld
Adjustable in 10 steps from 0.5 to 12 /15 s or 17 s:
t
ld
is the tripping time with 6 x I
r
The ETU350 LSI has a permanently active thermal memory.
Short-time delayed short circuit protection S:
•
I
sd
Adjustable in 10 steps from 1.5 to 9 / 10 x I
r:
•
t
sd
Adjustable in 6 steps from 0 to 0.4 s
with the reference point at I
sd
= 8 x I
r
The curve shape is I
2
t = constant.
Instantaneous short-circuit protection I:
•
I
i
Not adjustable: Permanently set to 9 / 10 / 11 / 12 x I
n
(depending on rated operational current and breaker frame size)
Neutral conductor protection N:
The neutral conductor protection function is available for 4-pole molded case circuit breakers
only.
•
I
N
I
n
< 100 A: 1.0 x I
r
or OFF
I
n
≥ 100 A: 0.5 / 1.0 x I
r
or OFF
