Siemens SENTRON 3WA1 - Page 206

Applications
3.2 Using the 3WA circuit breaker for motor protection
3WA1 air circuit breaker
204 Equipment Manual, 02/2023, 92310000002-06
Non-tripping of the circuit breaker due to the inrush peak current of electric motors and
simultaneous protection in case of rotor blocking can be achieved by setting tripping
time t
sd
of the delayed short-circuit protection ST to 0.02 s.
Protective function Setting range for parameter sets A
and B
Settings with rotary switch only
possible in parameter set A
S: Delayed short circuit protection ST
Tripping
Can be switched on/off
Current setting I
sd
0.6 x I
n
… 0.8 x I
cw
1.5 / 2 / 2.5 / 3 / 4 / 5 / 6 / 8 / 10 x I
r
Tripping time t
sd
0.02 … 0.4 s
At I
2
t = OFF:
0.08 / 0.15 / 0.22 / 0.3 / 0.4 s
At I
2
t = ON:
0.1 / 0.2 / 0.3 / 0.4 s
Characteristic ST curve
I
0
t / I
2
t
Reference point I
ST ref
6 … 12 x I
r
Intermittent detection
Can be switched on/off
This can be set using the operating keys on the display or with the help of the SENTRON
powerconfig configuration software via Bluetooth or communication. For protection
parameter set A, the setting is made under display menu item 3.1.3 of the ETU600.