Description
2.8 Electronic trip unit ETU
3VA27 molded case circuit breakers & 3WL10 air circuit breakers
Manual, 10/2018, L1V30499596002-01
75
Protection functions of the ETU
ETU650 LSI
ETU660 LSIG
Switchover to alternative operating values with
short-time-delayed short-circuit current during
the switch-on phase (inrush adaptation) for
tripping characteristic t=k (fixed) possible
●
Default value: OFF
●
Default value: OFF
Setting range of the switch-on phase (inrush
adaptation)
0.1 to 30 s (in steps of 0.01)
Default value: 0.1
0.1 to 30 s (in steps of 0.01)
Default value: 0.1
Setting range Isd = In x … during the switch-on
phase (inrush adaptation)
0.6 to 10 (in steps of 0.1)
Default value: 10
0.6 to 10
(in steps of 0.1)
Default value: 10
I
INST: Instantaneous short-circuit protection I
i
Protection function can be enabled/disabled
●
●
Setting range for operating value I
i
= I
n
x …
1.5 to 15 (in steps of 0.1)
Default value: 2
Tolerance
1)
: ± 10%
1.5 to 15 (in steps of 0.1)
Default value: 2
Tolerance
1)
: ± 10%
Switchover to alternative operating values with
instantaneous short-circuit current during the
switch-on phase (inrush adaptation) for tripping
characteristic t=k (fixed) possible
●
Default value: OFF
●
Default value: OFF
Setting range of the switch-on phase (inrush
adaptation)
0.10 to 30 s (in steps of 0.01)
Default value: 0.1
Tolerance
1)
: ≤ 30 ms
0.10 to 30 s (in steps of 0.01)
Default value: 0.1
Tolerance
1)
: ≤ 30 ms
Setting range I
i
= I
n
x … during the switch-on
phase (inrush adaptation)
1.5 to 15 (in steps of 0.1)
Default value: 1.5
1.5 to 15 (in steps of 0.1)
Default value: 1.5
N
Neutral protection
Neutral protection can be enabled/disabled
●
●
Current setting value I
N
= I
n
x …
50%; 100%; 150%; 200%
50%; 100%; 150%; 200%
G
GF: Ground-fault protection
Protection function can be enabled/disabled
—
●
Characteristic
—
I²t / t = constant
Default value: t = constant
Setting range for operating value I
g
= I
n
x …
—
0.1 to 1 (in steps of 0.001)
Default value: 0.1
Tolerance
1)
: ± 7%
Setting range for delay time t
g
(fixed) t=k
—
0.1 to 1 s (in steps of 0.05)
Default value: 0.1s
Tolerance
1)
: The better value
out of ± 10% or ± 40 ms or
50 ms with
t
g
= instantaneous
Setting range for delay time t
g
at I²t (reference
point 2 x I
g
)
—
0.1 to 1 s (in steps of 0.05)
Ground-fault protection pre-alarm
—
50 to 90% x I
r
(in steps of
1%)
Default value: 90%
Tripping can be deactivated
—
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