Siemens SENTRON 3WA1 - Activation Limits and Power Supply

Description
2.3 Protection system
3WA1 air circuit breaker
76 Equipment Manual, 02/2023, 92310000002-06
2.3.8 Activation limits and power supply
The electronic trip unit does not require auxiliary power. The electronic trip unit is
powered by the circuit breaker's internal current sensors. Depending on the operational
current, the electronic trip unit of the circuit breaker is activated from:
Sizes 1 / 2 / 3
ACT LED (Active)
Description
1-pole/2-pole/3-
pole load
70 A
Flashing
(frequency: 1 Hz)
Electronic trip unit active
ETU600: Display off
110 A
Flashing
(frequency: 1 Hz)
Electronic trip unit active
ETU600: Display on
150 A
Flashing
(frequency: 1 Hz)
Electronic trip unit active
ETU600: Display on
TUI600: active
If you use functions with data exchange via the CubicleBUS
2
with the ETU600 electronic
trip unit, an external 24 V DC power supply must be connected to the secondary
disconnect terminals X8-3 and X8-4. This means that the ETU600 is active even when
the circuit breaker is open or when the operational current is below the activation limit.
WARNING
Loss of direct-acting circuit breaker functionality with option code Z = K60
(internal current sensors, without energy cores, for applications with frequency
converters)
When the circuit breaker is equipped with current sensors without energy cores, the
electronic trip unit is not self-powered.
For these applications, an undervoltage release and an external 24 V DC power supply
are required for activating the electronic trip unit.
The auxiliary power supplying the electronic trip unit is internally coupled to the
undervoltage release of the circuit breaker.