Draw-out circuit breaker with Sentinel trip unit 55 kA 400 A 4P HW1M404DB

Sliding circuit breaker with sentinel trip unit – 400 A, 4P, 55 kA

This device is an air‑type circuit breaker with a high breaking capacity, designed for industrial and commercial installations where reliability and easy access to internal components are required. Its sliding construction allows safe and quick servicing without disconnecting the conductors – simply pull the block out of the housing.

It protects circuits with a rated current of 400 A at voltages up to 690 V. A short‑circuit rating of 55 kA means the device can safely interrupt very large fault currents – essential in high‑power supply systems or installations near transformers.

The breaker has four poles and is equipped with four auxiliary switching contacts. This enables integration with control, signalling, or interlock systems – e.g., for monitoring trip status, activating interlocks, or connecting alarms. It has no make‑before‑break or make‑after‑break auxiliary contacts, avoiding unnecessary functions that could complicate installation or increase cost.

There is no built‑in motorised drive, but an optional drive can be fitted, providing flexibility for upgrades or remote operation. The unit is not intended for DIN‑rail mounting – its construction requires mounting in a cabinet or enclosure.

IP2X protection offers basic protection against accidental contact with live parts, meeting safety requirements for closed cabinets. The breaker does not include an overload indicator or ground‑fault protection – its function is solely to open and close under overload and phase‑fault conditions.

A clear trip indicator provides a visible, physical confirmation of the device’s state, simplifying diagnostics and enhancing safety: operators do not have to guess whether the breaker is open or closed.

Main circuit connections are made through a separate part of the housing, meaning wiring is performed outside the main block. This simplifies installation and service: the entire module can be disconnected without disturbing the cables.

The breaker does not contain a built‑in under‑voltage release or integrated protection – it operates purely as a mechanical breaker with a thermal‑magnetic (sentinel) trip unit. In other words, it reacts to overload and short‑circuit conditions, but not to voltage drops or phase imbalance.

This solution is aimed at installers who need a robust, simple, and serviceable device without unnecessary features. For the end user, this translates into fewer failures, easier diagnostics, and longer lifespan.