Siemens SENTRON 3WA1 - ETU300 Electronic Trip Unit; Overview of Variants

Description
2.4 ETU300 electronic trip unit
3WA1 air circuit breaker
Equipment Manual, 02/2023, 92310000002-06
77
2.4 ETU300 electronic trip unit
2.4.1 Overview of variants
All circuit breakers with integrated ETU300 electronic trip units have a microprocessor.
In contrast to the ETU600 electronic trip unit, it is not possible to extend the functions by
adding additional function packages. For necessary function extensions, it is possible to
replace the ETU300 electronic trip unit with the ETU600 and use its modularity.
The protective functions of the ETU300 comply with the regulations for electrical
installations and protect them against overcurrent and short circuit. The ETU300
electronic trip unit is available in the following versions:
• ETU300 LSI
This version has overload protection, short-time and instantaneous short-circuit
protection as basic protective functions. The basic protective functions do not require
an auxiliary power supply; they are supplied by the current flowing through the circuit
breaker.
• ETU300 LSIG
In addition to the basic protective functions of the ETU300 LSI, this version offers
ground-fault protection with a permanently set current setting and tripping time.