Description
2.8 Electronic trip unit ETU
3VA27 molded case circuit breakers & 3WL10 air circuit breakers
72
Manual, 10/2018, L1V30499596002-01
2.8.5
Parameters of the trip units
The parameter values of the trip units that can be set are listed below.
Electronic trip units of the 3-series
Protection functions of the ETU
ETU320 LI
ETU350 LSI
ETU360 LSIG
L
LT: Overload protection
Setting range of operating value I
r
= I
n
x
…
0.4; 0.5: 0.6; 0.7; 0.75;
0.8; 0.85; 0.9; 0.95; 1
Default value: 0.4
Tolerance
1)
: Tripping
between 1.05 and
1.2 x I
r
0.4; 0.5: 0.6; 0.7; 0.75;
0.8; 0.85; 0.9; 0.95; 1
Default value: 0.4
Tolerance
1)
: Tripping
between 1.05 and
1.2 x I
r
0.4; 0.5: 0.6; 0.7; 0.75;
0.8; 0.85; 0.9; 0.95; 1
Default value: 0.4
Tolerance
1)
: Tripping
between 1.05 and
1.2 x I
r
Setting range for delay time t
r
at I²t
(reference point 6 x I
r
)
0.75; 1; 2; 5; 8; 10; 14;
17; 21; 25 s
Default value: 0.75 s
Tolerance
1)
:
± 10% I ≤ 6 x I
n
± 20% I > 6 x I
n
0.75; 1; 2; 5; 8; 10; 14;
17; 21; 25 s
Default value: 0.75 s
Tolerance
1)
:
± 10% I ≤ 6 x
I
n
± 20% I > 6 x I
n
0.75; 1; 2; 5; 8; 10; 14;
17; 21; 25 s
Default value: 0.75 s
Tolerance
1)
:
± 10% I ≤ 6 x I
n
± 20% I > 6 x I
n
Overload pre-alarm
50 to 100% x I
r
(in steps of 1%)
Default value: 90%
50 to 100% x I
r
(in steps of 1%)
Default value: 90%
50 to 100% x I
r
(in steps of 1%)
Default value: 90%
S
ST: Short-time-delayed short-circuit protection
Protection function can be enab-
led/disabled
—
●
●
Setting range of operating value I
sd
= I
n
x …
—
1; 1.5; 2; 2.5; 3; 4; 6;
8; 10
Default value: OFF
Tolerance
1)
:
± 7% I ≤ 6 x I
n
± 10% I ≤ 6 x I
n
1; 1.5; 2; 2.5; 3; 4; 6;
8; 10
Default value: OFF
Tolerance
1)
:
± 7% I ≤ 6 x I
n
± 10% I ≤ 6 x I
n
Characteristic (switchover possible)
—
I²t / t = constant
I²t / t = constant
Setting range for delay time t
sd
(fixed
delay) t=k
—
0.08; 0.15; 0.22; 0.3;
0.4
Tolerance
1)
: The better
value out of ± 10% or
± 40ms
0.08; 0.15; 0.22; 0.3;
0.4
Tolerance
1)
: The better
value out of ± 10% or
± 40ms
Setting range for delay time t
sd
at I²t
(reference point 10 x I
n
)
—
0.1; 0.2; 0.3; 0.4; 0.5
Default value: 0.1
0.1; 0.2; 0.3; 0.4; 0.5
Default value: 0.1
I
INST: Instantaneous short-circuit protection
Protection function can be enab-
led/disabled
●
●
●
Setting range for operating value I
i
= I
n
x …
1.5; 2; 3; 4; 6; 8; 10;
12; 15
Default value: 1.5
Tolerance
1)
: ± 10%
1.5; 2; 3; 4; 6; 8; 10;
12; 15
Default value: 1.5
Tolerance
1)
: ± 10%
1.5; 2; 3; 4; 6; 8; 10;
12; 15
Default value: 1.5
Tolerance
1)
: ± 10%
N
Neutral protection
