Stationary circuit breaker with sentinel trip unit, 55 kA, 800 A, 3P HW1M308FB

Stationary air circuit breaker with Sentinel trigger

This device is a stationary air circuit breaker with a rated current of 800 A, intended for installation in medium‑voltage switchgear – primarily in industrial and commercial installations where high breaking capacity and reliability are required. It operates in a voltage range of 440 V to 690 V, and its short‑circuit rating is 55 kA at 400 V, meaning it can safely interrupt circuits during high‑energy faults, even in locations with high fault power.

It has three poles and main contacts connected via a busbar connection – facilitating integration with busbars and eliminating the need for cable wiring. The device is not mounted on a DIN or TH rail; its construction requires permanent mounting on a panel or switchgear frame. It does not contain an internal motor drive but supports an optional drive, allowing remote control or system automation without replacing the entire unit.

The assembly includes four auxiliary switching contacts – used for status indication (on/off) or for controlling auxiliary circuits, e.g., alarms or SCADA interfaces. An integrated trip indicator allows quick location of the fault cause without opening the enclosure. Absence of earth‑fault protection means this protection must be provided by additional devices (e.g., residual‑current circuit breakers or protections in the Sentinel trigger).

The IP2X protection rating provides basic protection against accidental contact with live parts – sufficient for installations in closed rooms, but not suitable for humid or outdoor environments. The device does not contain a built‑in over‑voltage trigger or any other protective functions – all protection parameters are set by an external unit (the Sentinel trigger), which must be installed separately.

The gross weight is 44 kg, indicating a robust construction and a large amount of metal material in the enclosure. This device is intended for professionals: installers working on large facilities who need a reliable switchgear component that can be easily configured and integrated with automation systems. It is not a “replace‑as‑you‑go” product – its installation requires planning and an appropriate location in the switchgear.

No additional overload or short‑circuit protection is required – this task is performed by the Sentinel trigger, which is part of the system, not this device. The breaker itself functions solely as a mechanical element that makes and breaks the circuit.