SIEMENS WL Low Voltage Power Breakers & Insulated Case Circuit Breakers - Trip Units

During development of our electronic trip units, we have consistently striven to ensure modularity. The following are just some of the modules that are simple to retrofit the trip units themselves at any time:

  • Ground fault protection - optional device that detects fault currents that flow to ground and represent a fire hazard to the system. The adjustable time delay allows selective staggering of consecutively arranged circuit breakers.

  • Communication - via the breaker internal system bus called CubicleBUS, the WL circuit breaker can be connected to additional input and output modules as well as Profibus or Modbus communication modules.  This opens up a range of opportunities to reduce secondary device count/wiring and to increase functionality implemented in power distribution systems.

  • Metering Function - provides a viable alternative to external multi-function measuring instruments in many applications. The internal metering function can measure currents, voltages, power, energy, power factor and frequency.  This function also includes two independent wave form buffers which support harmonic analysis. With these buffers, the current and voltage waveforms can be recorded and detailed diagnostic triggering on events is possible.

  • Displays - different types for various applications are available, i.e. high contrast LCD displays with adjustable angle viewing and background light for inadequate light conditions.

  • Rating plug - replaceable module that enables users to reduce the rated device current for optimum adaptation to the system, e.g. during startup of a plant section.


ETU755

Application

Trip unit with remote-only parameter setting for special application demands - CubicleBUS integrated


Main features

  • Adjustable long time overload protection with time delay

  • Adjustable short-time delay short-circuit protection

  • Adjustable instantaneous short-circuit protection

  • Replaceable rating plug allows instant adaptability to the required plant currents, thus ensuring overload protection of 200A to 5000A

  • Overcurrent alarm indicator

  • LED trip cause indicator

  • Option for testing the trip unit

  • Detection of the energy flow direction

  • Protective parameters set via communications or Breaker Data Adapter (BDA)

  • Two independent sets of protective parameters, remotely selectable

  • Thermal memory for improved protection of motor loads

  • Selectable neutral conductor protection using external neutral sensor

  • Modular ground fault protection, with separately adjustable alarm and trip function (option)

  • Communication interface, for optional metering function, connection of external modules as option or retrofit

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