Stationary circuit breaker with Sentinel trip unit 55kA 400A 3P HW1M304FB

Stationary circuit breaker with Sentinel trip unit – 55 kA, 400 A, 3P

This device is a fixed, non‑withdrawable version of an air circuit breaker integrated with a Sentinel trip unit. It is designed for installation in medium‑ and high‑current switchboards where high making capacity and stability during fault conditions are required. A rating of 55 kA at 400 V means it can safely interrupt the circuit even under extreme short‑circuit conditions without risk of damage to the device.

It has three poles and a busbar connection – meaning it does not use traditional screws or fittings, but is connected directly to the distribution busbars. This simplifies installation and eliminates failure points associated with loose connections. It cannot be mounted on a DIN rail – it is a stationary device that must be permanently fixed in an enclosure.

A built‑in trip indicator is an advantage: after the protection activates, you can physically see that the breaker has opened – no need to guess whether it was an over‑voltage or an over‑current event. This facilitates diagnostics and safety during service.

It provides four auxiliary changeover contacts – which can be used for status signalling (e.g., “off”, “closed”) or for controlling other circuits via a PLC. There are no make or break contacts – thus no additional normally‑closed or normally‑open contacts without switching.

The rated voltage operates in the range of 440 V to 690 V – making it suitable for both 400 V and 690 V networks common in industry. The IP2X protection class offers only basic protection against touch of live parts – it does not protect against dust or water. The device is installed in enclosures with the appropriate protection class.

It does not have an integrated motor drive – but one can be added optionally. This means that if remote control is required (e.g., via a BMS), a motorised drive can be added without replacing the whole unit. It also lacks ground‑fault protection and an under‑voltage trip – so if protection against earthing faults or over‑voltages is needed, it must be provided externally.

The unit is not supplied with additional protection – the Sentinel trip unit is the only protective element. There are no extra functions such as “overload + time delay” – only the standard Sentinel trip unit characteristics (factory‑set).

This solution is for the installer: quick rail mounting, clear status indication, and the possibility of expansion with a motor drive. For the end user: robust short‑circuit protection, no surprises during a fault thanks to the visible indicator.