It carries a 187 kA interrupting capacity at 240 V and still holds 121 kA at 415 V and 440 V — that's extreme SCCR for a 40 A frame, meaning it can sit upstream of a high-fault panel without cascading failure.
Above 50 °C it rolls off gradually: 38.4 A at 55 °C, 37.6 A at 60 °C, 36.8 A at 65 °C, and 36 A at 70 °C. That 10% drop at the top end still leaves headroom for a 30 A motor load in a hot cabinet. The 75 W maximum power loss means you need to account for heat dissipation if the breaker is packed tight with other devices.
Built-in undervoltage release and auxiliary signaling
This variant includes an integrated undervoltage release (UVR) — no external module needed. The trip indicator on the front gives a local visual flag when the breaker has tripped on fault.
Motor protection with ETU350M
The ETU350M electronic trip unit is configured for motor protection — it includes phase failure detection (monitors all three phases) and an LSI trip curve (long-time, short-time, instantaneous). That means it can protect a motor against overload, short circuit, and single-phasing without a separate motor protection relay. The 20 000 latching endurance cycles reflect the mechanical life of the switching mechanism under normal operation.