Siemens SENTRON 3WL Reference Manual page 35

3WL Air Circuit Breakers/Non-Automatic Air Circuit Breakers up to 6300 A (AC)
Every solid-state release type and every setting has its own cha-
racteristic curve. Only a selection is shown in the following. The
characteristic curves each show the largest and smallest setting
range of SENTRON 3WL circuit breakers with 1000 A rated cur-
rent at 500 V rated voltage with various releases. In order to ob-
tain a complete tripping characteristic, the relevant parts of the
characteristics have to be combined.
The characteristic curves show the behavior of the solid-state re-
lease when it is activated by a current that is already flowing be-
fore the tripping operation. If the overcurrent tripping occurs im-
mediately after switch on and the solid-state release is therefore
not yet enabled, the opening ime is extended, depending on the
level of the overcurrent by up to 15 ms. In order to determine the
break-times of the circuit breakers, approximately 15 ms must
be added to the opening times shown for the arcing time.
Refer to the following table for tolerances.
The characteristic curves shown apply to ambient temperatures
at the circuit breaker between -5 and +55 °C. The release can be
operated at ambient temperatures of -20 to +70 °C (ETU76B
with graphics display up to +55 °C). An extended tolerance
band can apply at these temperatures.
10000
R
0,4 ... 1,0 x
1000
n
100
10
1
0,1
0,01
0,1 1
SENTRON 3WL circuit breaker with ETU45B and ETU76B solid-state
release, L characteristic curve
10000
1000
100
10
1
0,1
0,01
0,1 1
SENTRON 3WL circuit breaker with ETU45B and ETU76B solid-state
release, I characteristic curve
2)
4
= const
2
= const
R
2
2 ... 30s for
4
1 ... 5s for
10 100
/
n
i
1,5 x ... 0,8 x
n
cs
10 1
/ /
n cs
3WL Air Circuit Breakers
10000
1000
100
g
10
100 ... 1200 A 1)
1
0,1
0,01
100 1000
SENTRON 3WL circuit breaker with ETU45B and ETU76B solid-state
release, G characteristic curve
10000
1000
100
10
1
0,1
0,01
0,1 1
SENTRON 3WL circuit breaker with ETU76B solid-state release,
S characteristic curve
Further characteristic curves are shown in the manual and the
planning and configuring tool SIMARIS deSign, or ask your
Siemens contact person.
Tolerances for the set currents
L: tripping operations between 1.05 and 1.2 × I
S: –0 %, +20 %
I: –0 %, +20 %
G: –0 %, +20 %
Tolerances for the tripping times
2
L: –20 %, +0 % for I t characteristic curve
S: –0 %, +60 ms or -0 %, 10 % for tripping times greater than 600 ms
I: < 50 ms
G: –0 %, +60 ms or -0 %, 10 % for tripping times greater than 600 ms
1) Sizes I and II: 100 ... 1200 A
Size III: 400 ... 1200 A.
2) With single-pole loading in the lowest rated current range, the response
times of the short-circuit release can be extended by approx. 10 % and
the tripping times by approx. 15 % compared to the characteristic curve.
Project planning aids
0,1 ... 0,5 s
g
10000 100000
A
sd
1,25 x ... 0,8 x
n cw
2
= const
sd
= const
sd
0,1 ... 0,4 s
0,02 ... 4 s
10 1
/
/
n cw
R
Siemens · 2009 35