Siemens SENTRON 3WL10, Manual

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Description
2.2 Possible uses and portfolio
Air circuit breaker 3WL10
Manual, 11/2017, L1V30499596002-01
17
Portfolio
The 3WL10 air circuit breaker is part of the Siemens 3WL range, which covers all breaking
capacity classes between B and C.
BG Frame size
Frame size and breaking capacity classes
The 3WL10 air circuit breaker has size 0 and is suitable for:
● Rated currents between 630 A and 1250 A
● Rated voltages up to 690 V
The available breaking capacity classes are 42 kA, 55 kA and up to 66 kA at 440 V AC.
Selective response
With its contact system, the 3WL10 air circuit breaker is designed for time-selective
time-delayed tripping.
● A short-circuit-induced trip can be delayed for up to 400 ms (short-time-delayed
short-circuit protection ST).
● For maximum requirements, the instantaneous short-circuit protection (INST) can be
disabled to temporarily deactivate or increase the response threshold of the short-circuit
protection ST up to the I
cw
value of the device. After this utilizable time and current limit
has been exceeded, the circuit breaker instantaneously trips within 10 ms and interrupts
the overcurrent within 30 ms.
These settings give downstream devices time to clear the fault in the feeder affected (time-
selective response, thus ensuring maximum availability).
On the other hand, a system can be protected specifically by optimization of the circuit
breaker for fast response. In this case, it clears a lower-level fault as quickly as possible,
irrespective of selective response.