The DOMF01340 is a 3-pole miniature circuit breaker from Schneider Electric's Domae range, rated 40 A with a C trip curve and 6 kA breaking capacity per IEC 60898-1.
For a 3-phase distribution sub-feed, that's roughly 27 kW of connected load at 400 V line-to-line — enough for a small machine cell or a lighting distribution board. The thermal-magnetic trip unit combines a bimetal strip for overload protection (slow response to sustained overcurrent) and a solenoid for short-circuit protection (instantaneous above the magnetic threshold). The C curve's 5 to 10 x In magnetic trip range means the breaker holds through the inrush of a small motor or a bank of fluorescent ballasts but still clears a hard fault fast enough to protect the downstream cable. The operating temperature range of -5 to 60 °C covers most heated or ventilated enclosures, and the 95 % humidity at 55 °C rating (tropicalisation class 2 per IEC 60068-1) means it won't corrode or track in a humid plant environment. Mechanical durability of 20,000 cycles and electrical durability of 10,000 cycles under rated load are typical for this class of MCB. For a panel that sees daily on-load switching (like a machine disconnect), 10,000 electrical cycles translates to roughly 27 years of one operation per day — not a wear-out concern in most installations.
Integration notes
The breaker occupies 6 module pitches at 9 mm each (54 mm total width) on a DIN rail. The 18 mm phase-to-phase connection pitch matches standard busbar systems for the Domae range, so you can feed all three poles from a single comb busbar without extra jumpers. Tunnel terminals accept up to 35 mm² rigid or 25 mm² flexible cable; strip 14 mm and torque to 3.5 N.m. The toggle actuator gives clear visual indication of the contact position — no ambiguity when you're racking out a panel.