The built-in undervoltage release (UVR) means it drops the load if supply voltage falls below a set threshold, which is standard for motor feeder protection or emergency-off circuits where you don't want automatic reclosure. At 70 mm deep, 101.6 mm wide, and 130 mm tall, this breaker fits the standard SENTRON 3VA panel footprint — no surprises when you're swapping into an existing DIN-rail or mounting-plate layout. The 40 A rating holds flat from 40 °C up to 50 °C, then derates slightly to 37 A at 70 °C ambient, so you've got headroom in a warm enclosure without recalculating the whole branch.
Breaking capacity across voltages — selectivity planning
The interrupting ratings step down as voltage climbs: 187 kA at 240 V, 121 kA at 415 V, 75.6 kA at 440 V, and a floor of 17 kA at 500 V and 690 V.
Panel fit and thermal derating
Four poles in a 101.6 mm wide package. The 70 mm depth clears most shallow enclosures; the 130 mm height fits alongside other SENTRON devices. At 13.3 W maximum power loss, account for dissipation when stacking multiple breakers in a sealed enclosure.