LZM3 4-pole power circuit breaker Ir=315-630A LZMN3-4-AE630-I 116476

Protection of main circuits in industrial installations

This four-pole power circuit breaker from the Power Defense series by Eaton (model LZMN3) is a device designed for protecting high-current circuits where precise adjustment and high switching capacity are required. With a rated continuous current of 630 A and the ability to set the overload release in the range of 315 to 630 A, the device is ideal for main distribution boards, powering high-power motors, or transformers. Thanks to the electronic protective unit, the installer has full control over the tripping characteristic, allowing the protection to be adapted to the specifics of the connected loads without the need to replace the entire device when the load changes.

Precision of settings and resistance to short-circuit current surges

A key advantage of this model is the flexibility in configuring short-circuit protection. The short-circuit release can be set in the range of 1260 A to 5040 A, meaning the device will not trip incorrectly during short-term current surges typical of electric motor starting, while simultaneously disconnecting the circuit quickly in the event of a real short circuit. At a rated voltage of 400 V, the circuit breaker guarantees a short-circuit breaking capacity (Icu) of 50 kA, ensuring safety even in systems with high short-circuit powers. The entire unit operates in systems with voltages up to 690 V AC, covering most standard industrial and commercial applications.

Design facilitating installation and maintenance

The device has been designed with convenient operation in mind, both during installation and subsequent operation. Main circuit terminals are located on the front side and are implemented via screw connections, facilitating the connection of thick cables or busbars (up to 240 mm² cross-section for aluminum conductors). The operating handle allows for manual switching on and off of the circuit, while an optional motor drive provides the possibility of remote control – useful in building automation or industrial systems. The IP20 degree of protection guards against accidental contact with live parts (in accordance with DIN EN 50274), and the lack of built-in auxiliary contacts means a pure protective function without unnecessary additions – their absence can be easily supplemented with external modules if needed.

It is worth noting that this device is of the "fixed mounting" type, which requires permanent mounting in the distribution cabinet. The lack of an off indicator in the standard enclosure is not a limitation – the handle position is visually clear. Thanks to compliance with IEC/EN 60947 standards and the VDE certificate, the circuit breaker meets the rigorous safety requirements applied in Europe. Its mechanical life reaches up to 15 thousand operating cycles, and the electrical life ranges from several to five thousand cycles depending on operating conditions (e.g., at 415 V AC-1), making it a durable component of the energy infrastructure.